Elbow Positioning and Joint Insufflation Substantially Influence Median and Radial Nerve Locations

Background

The median and radial nerves are at risk of iatrogenic injury when performing arthroscopic arthrolysis with anterior capsulectomy. Although prior anatomic studies have identified the position of these nerves, little is known about how elbow positioning and joint insufflation might influence nerve locations.

Questions/purposes

In a cadaver model, we sought to determine whether (1) the locations of the median and radial nerves change with variation of elbow positioning; and whether (2) flexion and joint insufflation increase the distance of the median and radial nerves to osseous landmarks after correcting for differences in size of the cadaveric specimens.

Methods

The median and radial nerves were marked with a radiopaque thread in 11 fresh-frozen elbow specimens. Three-dimensional radiographic scans were performed in extension, in 90° flexion, and after joint insufflations in neutral rotation, pronation, and supination. Trochlear and capitellar widths were analyzed. The distances of the median nerve to the medial and anterior edge of the trochlea and to the coronoid were measured. The distances of the radial nerve to the lateral and anterior edge of the capitulum and to the anterior edge of the radial head were measured. We analyzed the mediolateral nerve locations as a percentage function of the trochlear and capitellar widths to control for differences regarding the size of the specimens.

Results

The mean distance of the radial nerve to the lateral edge of the capitulum as a percentage function of the capitellar width increased from 68% ± 17% in extension to 91% ± 23% in flexion (mean difference = 23%; 95% confidence interval [CI], 5%–41%; p = 0.01). With the numbers available, no such difference was observed regarding the location of the median nerve in relation to the medial border of the trochlea (mean difference = 5%; 95% CI, −13% to 22%; p = 0.309). Flexion and joint insufflation increased the distance of the nerves to osseous landmarks. The mean distance of the median nerve to the coronoid tip was 5.4 ± 1.3 mm in extension, 9.1 ± 2.3 mm in flexion (mean difference = 3.7 mm; 95% CI, 2.04–5.36 mm; p < 0.001), and 12.6 ± 3.6 mm in flexion and insufflation (mean difference = 3.5 mm; 95% CI, 0.81–6.19 mm; p = 0.008). The mean distance of the radial nerve to the anterior edge of the radial head increased from 4.7 ± 1.8 mm in extension to 7.7 ± 2.7 mm in flexion (mean difference = 3.0 mm; 95% CI, 0.96–5.04 mm; p = 0.005) and to 11.9 ± 3.0 mm in flexion with additional joint insufflation (mean difference = 4.2 mm; 95% CI, 1.66–6.74 mm; p = 0.002).

Conclusions

The radial nerve shifts medially during flexion from the lateral to the medial border of the inner third of the capitulum. The median nerve is located at the medial quarter of the joint. The distance of the median and radial nerves to osseous landmarks doubles from extension to 90° flexion and triples after joint insufflation.

Clinical Relevance

Elbow arthroscopy with anterior capsulectomy should be performed cautiously at the medial aspect of the joint to avoid median nerve lesions. Performing arthroscopic anterior capsulectomy in flexion at the lateral aspect of the joint and in slight extension at the medial edge of the capitulum could enhance safety of this procedure.     

How Does?Bone Strength?Compare Across Sex,Site, and Ethnicity?

Background

The risk of fragility fractures in the United States is approximately 2.5 times greater among black and white women compared with their male counterparts. On average, men of both ethnicities have wider bones of greater cortical mass compared with the narrower bones of lower cortical mass among women. However, it remains uncertain whether the low cortical area observed in the long bones of women is consistent with their narrower bone diameter or if their cortical area is reduced beyond that which is expected for the sex differences in body size and external bone size.

Questions/purposes

We asked (1) do black and white women consistently have narrower bones of less strength across long bones compared with black and white men; and (2) do all long bones of black and white women have reduced cortical area compared with black and white men?

Methods

Peripheral quantitative CT was used to quantify bone strength and cross-sectional morphology from the major long bones of 125 white and 115 black adult men and women (20–35 years of age). Regression analyses were used to test for differences in bone strength and cortical area after for adjusting for either body size, bone size, or both.

Results

After adjusting bone strength for body size, regression analyses showed that black women had lower bone strength compared with black men (women: mean = 298.7–25,522 mg HA mm⁴, 95% confidence interval [CI], 270–27,692 mg HA mm⁴; men: mean = 381.6–30,945 mg HA mm⁴, 95% CI, 358.2–32,853 mg HA mm⁴; percent difference = 12%–38%, p = 0.06–0.0001). Similarly, white women also had lower bone strength compared with white men (women: mean = 229.5–22,892 mg HA mm⁴, 95% CI, 209.3–24,539 mg HA mm⁴; men: mean = 314.3–29,986 mg HA mm⁴, 95% CI, 297.3–31,331 mg HA mm⁴; percent difference = 27%–49%, p = 0.0001). All long bones of women for both ethnicities showed lower cortical area compared with men. After accounting for both body size and external bone size, black women (women: mean = 43.25–357.70 mm², 95% CI, 41.45–367.52 mm²; men: mean = 48.06–400.10 mm², 95% CI, 46.67–408.72; percent difference = 6%–25%, p = 0.02–0.0001) and white women (women: mean = 38.53–350.10 mm², 95% CI, 36.99–359.80 mm²; men: mean = 42.06–394.30 mm², 95% CI, 40.95–402.10 mm²; percent difference = 6%–22%, p = 0.02–0.0001) were shown to have lower cortical area than their male counterparts. Therefore, the long bones of women are not only more slender than those of men, but also show a reduced cortical area that is 6% to 25% greater than expected for their external size, depending on the bone being considered.

Conclusions

The long bones of females are not just a more slender version of male long bones. Women have less cortical area than expected for their body size and bone size, which in part explains their reduced bone strength when compared with the more robust bones of men.

Clinical Relevance

The outcome of this assessment may be clinically important for the development of diagnostics and treatment regimens used to combat fractures. Future work should look at how the relationship among parameters reported here translates to the more fracture-prone metaphyseal regions.     

Women Build Long Bones With Less Cortical Mass Relative to Body Size and Bone Size Compared With Men

Background

The twofold greater lifetime risk of fracturing a bone for white women compared with white men and black women has been attributed in part to differences in how the skeletal system accumulates bone mass during growth. On average, women build more slender long bones with less cortical area compared with men. Although slender bones are known to have a naturally lower cortical area compared with wider bones, it remains unclear whether the relatively lower cortical area of women is consistent with their increased slenderness or is reduced beyond that expected for the sex-specific differences in bone size and body size. Whether this sexual dimorphism is consistent with ethnic background and is recapitulated in the widely used mouse model also remains unclear.

Questions/purposes

We asked (1) do black women build bones with reduced cortical area compared with black men; (2) do white women build bones with reduced cortical area compared with white men; and (3) do female mice build bones with reduced cortical area compared with male mice?

Methods

Bone strength and cross-sectional morphology of adult human and mouse bone were calculated from quantitative CT images of the femoral midshaft. The data were tested for normality and regression analyses were used to test for differences in cortical area between men and women after adjusting for body size and bone size by general linear model (GLM).

Results

Linear regression analysis showed that the femurs of black women had 11% lower cortical area compared with those of black men after adjusting for body size and bone size (women: mean = 357.7 mm²; 95% confidence interval [CI], 347.9–367.5 mm²; men: mean = 400.1 mm²; 95% CI, 391.5–408.7 mm²; effect size = 1.2; p < 0.001, GLM). Likewise, the femurs of white women had 12% less cortical area compared with those of white men after adjusting for body size and bone size (women: mean = 350.1 mm²; 95% CI, 340.4–359.8 mm²; men: mean = 394.3 mm²; 95% CI, 386.5–402.1 mm²; effect size = 1.3; p < 0.001, GLM). In contrast, female and male femora from recombinant inbred mouse strains showed the opposite trend; femurs from female mice had a 4% larger cortical area compared with those of male mice after adjusting for body size and bone size (female: mean = 0.73 mm²; 95% CI, 0.71–0.74 mm²; male: mean = 0.70 mm²; 95% CI, 0.68–0.71 mm²; effect size = 0.74; p = 0.04, GLM).

Conclusions

Female femurs are not simply a more slender version of male femurs. Women acquire substantially less mass (cortical area) for their body size and bone size compared with men. Our analysis questions whether mouse long bone is a suitable model to study human sexual dimorphism.

Clinical Relevance

Identifying differences in the way bones are constructed may be clinically important for developing sex-specific diagnostics and treatment strategies to reduce fragility fractures.     

Proceed? Mesh for Laparoscopic Ventral Hernia Repair

Background and Objectives:

Laparoscopic technique to repair ventral hernia offers advantages over conventional open surgery such as shorter recovery time, decreased pain, and lower recurrence rates. There are a myriad of meshes available for laparoscopic repair of ventral hernias. This study evaluated the outcomes of laparoscopic repair of ventral hernias with Proceed mesh (Ethicon, Somerville, NJ, USA) in a single academic institution.

Methods:

An institutional review board–approved retrospective review was performed for 100 consecutive patients with ventral hernia who underwent a laparoscopic approach at our institution from August 2006 to February 2009. All patients were operated on by a single surgeon using a standard technique with transabdominal suture fixation and tacks.

Results:

The study included 100 consecutive patients (57 female and 43 male patients). The mean age was 55 years (range, 16–78 years), and the mean body mass index was 33.3 kg/m² (range, 19.6–68.9 kg/m²). Of the repairs, 27% were performed for a recurrent hernia. The mean and median size of the defect were 128 cm² and 119.5 cm² (range, 4–500 cm²), respectively. To ensure appropriate mesh overlap, the mean size of mesh was 253 cm² (range, 36–700 cm²). There were 4 conversions. The mean operative time was 117 minutes (range, 35–286 minutes). The mean length of stay was 1.9 days. There were no major abdominal complications. With a mean follow-up period of 50 months (range, 38–68 months), we have not recorded any recurrences. No mesh-related complications have been documented.

Conclusions:

The laparoscopic approach to ventral hernia repairs using Proceed mesh is associated with a low conversion rate and no major complications. At 50 months of follow-up, the recurrence rate is 0%. There were no mesh-related complications.     

Bioburden Increases Heterotopic Ossification Formation in an Established Rat Model

Background

Heterotopic ossification (HO) develops in a majority of combat-related amputations wherein early bacterial colonization has been considered a potential early risk factor. Our group has recently developed a small animal model of trauma-induced HO that incorporates many of the multifaceted injury patterns of combat trauma in the absence of bacterial contamination and subsequent wound colonization.

Questions/purposes

We sought to determine if (1) the presence of bioburden (Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus [MRSA]) increases the magnitude of ectopic bone formation in traumatized muscle after amputation; and (2) what persistent effects bacterial contamination has on late microbial flora within the amputation site.

Methods

Using a blast-related HO model, we exposed 48 rats to blast overpressure, femur fracture, crush injury, and subsequent immediate transfemoral amputation through the zone of injury. Control injured rats (n = 8) were inoculated beneath the myodesis with phosphate-buffered saline not containing bacteria (vehicle) and treatment rats were inoculated with 1 × 10⁶ colony-forming units of A baumannii (n = 20) or MRSA (n = 20). All animals formed HO. Heterotopic ossification was determined by quantitative volumetric measurements of ectopic bone at 12-weeks postinjury using micro-CT and qualitative histomorphometry for assessment of new bone formation in the residual limb. Bone marrow and muscle tissue biopsies were collected from the residual limb at 12 weeks to quantitatively measure the bioburden load and to qualitatively determine the species-level identification of the bacterial flora.

Results

At 12 weeks, we observed a greater volume of HO in rats infected with MRSA (68.9 ± 8.6 mm³; 95% confidence interval [CI], 50.52–85.55) when compared with A baumannii (20.9 ± 3.7 mm³; 95% CI, 13.61–28.14; p < 0.001) or vehicle (16.3 ± 3.2 mm³; 95% CI, 10.06–22.47; p < 0.001). Soft tissue and marrow from the residual limb of rats inoculated with A baumannii tested negative for A baumannii infection but were positive for other strains of bacteria (1.33 × 10² ± 0.89 × 10²; 95% CI, −0.42 × 10²–3.08 × 10² and 1.25 × 10⁶ ± 0.69 × 10⁶; 95% CI, −0.13 × 10⁶–2.60 × 10⁶ colony-forming units in bone marrow and muscle tissue, respectively), whereas tissue from MRSA-infected rats contained MRSA only (4.84 × 10¹ ± 3.22 × 10¹; 95% CI, −1.47 × 10¹–11.1 × 10¹ and 2.80 × 10⁷ ± 1.73 × 10⁷; 95% CI, −0.60 × 10⁷–6.20 × 10⁷ in bone marrow and muscle tissue, respectively).

Conclusions

Our findings demonstrate that persistent infection with MRSA results in a greater volume of ectopic bone formation, which may be the result of chronic soft tissue inflammation, and that early wound colonization may be a key risk factor.

Clinical Relevance

Interventions that mitigate wound contamination and inflammation (such as early débridement, systemic and local antibiotics) may also have a beneficial effect with regard to the mitigation of HO formation and should be evaluated with that potential in mind in future preclinical studies.     

Upper cervical injuries – A rational approach to guide surgical management

Context

The complex anatomy and the importance of ligaments in providing stability at the upper cervical spine region (O–C1–C2) require the use of many imaging modalities to evaluate upper cervical injuries (UCI). While separate classifications have been developed for distinct injuries, a more practical treatment algorithm can be derived from the injury pattern in UCI.

Objective

To propose a practical treatment algorithm to guide treatment based on injuries characteristic of UCI.

Methods

A literature review was performed on the Pubmed database using the following keywords: (1) “occipital condyle injury”; (2) “craniocervical dislocation or atlanto-occipital dislocation or craniocervical dislocation”; (3) “atlas fractures”; and (4) “axis fractures”. Just articles containing the diagnosis, classification, and treatment of specific UCI were included. The data obtained were analyzed by the authors, dividing the UCI into two groups: Group 1 – patients with clear ligamentous injury and Group 2 – patients with fractures without ligament disruption.

Results

Injuries with ligamentous disruption, suggesting surgical treatment, include: atlanto-occipital dislocation, mid-substance transverse ligament injury, and C1–2 and C2–3 ligamentous injuries. In contrast, condyle, atlas, and axis fractures without significant displacement/misalignment can be initially treated using external orthoses. Odontoid fractures with risk factors for non-union are an exception in Group 2 once they are better treated surgically. Patients with neurological deficits may have more unstable injuries.

Conclusions

Ascertaining the status of relevant ligamentous structures, fracture patterns and alignment are important in determining surgical compared with non-surgical treatment for patients with UCI.     

Laparoscopic Radiofrequency Thermal Ablation for Uterine Adenomyosis

Background and Objectives:

Symptomatic uterine adenomyosis, unresponsive to medical therapy, is a challenging condition for patients who desire to preserve their uterus. This study was an evaluation of the feasibility and efficacy of laparoscopic radiofrequency thermal ablation of symptomatic nodular uterine adenomyosis.

Methods:

Fifteen women with symptomatic nodular adenomyosis, who had no plans for pregnancy but declined hysterectomy, underwent radiofrequency thermal ablation. Ultrasonography was performed at baseline and at postoperative follow-ups at 3, 6, 9, and 12 months. The impact of uterine adenomyosis–related symptoms was assessed according to the visual analog scale.

Results:

The median number of nodular lesions treated per patient was 1 (range, 1–2). The median baseline volume of the adenomyosis area was 60 cm³ (range, 18–128). The median reduction in volume was 32, 49.4, 59.6, and 65.4% at 3, 6, 9, and 12 months, respectively. A significant progressive improvement in the symptoms score was observed at the 4 follow-ups.

Conclusion:

In this study, laparoscopic radiofrequency thermal ablation reduced uterine adenomyosis–related symptoms and volume, with significant relief of symptoms.     

How Do Hindfoot Fusions Affect Ankle Biomechanics: A Cadaver Model

Background

While successful subtalar joint arthrodesis provides pain relief, resultant alterations in ankle biomechanics need to be considered, as this procedure may predispose the remaining hindfoot and tibiotalar joint to accelerated degenerative changes. However, the biomechanical consequences of isolated subtalar joint arthrodesis and additive fusions of the Chopart’s joints on tibiotalar joint biomechanics remain poorly understood.

Questions/purposes

We asked: What is the effect of isolated subtalar fusion and sequential Chopart’s joint fusions of the talonavicular and calcaneocuboid joints on tibiotalar joint (1) mechanics and (2) kinematics during loading for neutral, inverted, and everted orientations of the foot?

Methods

We evaluated the total force, contact area, and the magnitude and distribution of the contact stress on the articular surface of the talar dome, while simultaneously tracking the position of the talus relative to the tibia during loading in seven fresh-frozen cadaver feet. Each foot was loaded in the unfused, intact control condition followed by three randomized simulated hindfoot arthrodesis modalities: subtalar, double (subtalar and talonavicular), and triple (subtalar, talonavicular, and calcaneocuboid) arthrodesis. The intact and arthrodesis conditions were tested in three alignments using a metallic wedge insert: neutral (flat), 10° inverted, and 10° everted.

Results

Tibiotalar mechanics (total force and contact area) and kinematics (external rotation) differed owing to hindfoot arthrodeses. After subtalar arthrodesis, there were decreases in total force (445 ± 142 N, 95% CI, 340-550 N, versus 588 ± 118 N, 95% CI, 500–676 N; p < 0.001) and contact area (282 mm², 95% CI, 222–342 mm², versus 336 ± 96 mm², 95% CI, 265–407 mm²; p < 0.026) detected during loading in the neutral position; these changes also were seen in the everted foot position. Hindfoot arthrodesis also was associated with increased external rotation of the tibiotalar joint during loading: subtalar arthrodesis in the neutral loading position (3.3° ± 1.6°; 95% CI, 2°–4.6°; p = 0.004) and everted loading position (4.8° ± 2.6°; 95% CI, 2.7°–6.8°; p = 0.043); double arthrodesis in neutral (4.4° ± 2°; 95% CI, 2.8°–6°; p = 0.003) and inverted positions (5.8° ± 2.6°; 95% CI, 3.7°–7.9°; p = 0.002), and triple arthrodesis in all loaded orientations including neutral (4.5° ± 1.8°; 95% CI, 3.1°–5.9°; p = 0.002), inverted (6.4° ± 3.5°; 95% CI, 3.6°–9.2°; p = 0.009), and everted (3.6° ± 2°; 95% CI, 2°–5.2°; p = 0.053) positions. Finally, after subtalar arthrodesis, additive fusions at Chopart’s joints did not appear to result in additional observed differences in tibiotalar contact mechanics or kinematics with the number of specimens available.

Conclusions

Using a cadaveric biomechanical model, we identified some predictable trends in ankle biomechanics during loading after hindfoot fusion. In our tested specimens, fusion of the subtalar joint appeared to exert a dominant influence over ankle loading.

Clinical Relevance

A loss or deficit in function of the subtalar joint may be sufficient to alter ankle loading. These findings warrant consideration in the treatment of the arthritic hindfoot and also toward defining biomechanical goals for ankle arthroplasty in the setting of concomitant hindfoot degeneration or arthrodesis.     

Premature Therapeutic Antimicrobial Treatments Can Compromise the Diagnosis of Late Periprosthetic Joint Infection

Background

In the absence of positive cultures and draining sinuses, the diagnosis of periprosthetic joint infection (PJI) relies on laboratory values. It is unknown if administration of antibiotics within 2 weeks before diagnostic evaluations can affect these tests in patients with PJI.

Questions/purposes

The purpose of this study was to investigate the correlation of antibiotic administration with (1) fluctuations in the synovial fluid and serology laboratory values; and (2) sensitivity of the diagnostic tests in patients with late PJI (per Musculoskeletal Infection Society [MSIS] criteria).

Methods

Synovial white blood cell (WBC) count, polymorphonuclear neutrophil (PMN) percentage, and serum erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) as well as culture results were investigated in 161 patients undergoing total knee arthroplasty with late PJI diagnosed with the MSIS criteria. Depending on whether presampling antibiotics were used, patients were divided in two groups (53 [33%] patients were on antibiotics). The median laboratory values and the false-negative rates were compared between the two groups.

Results

The median of all variables were lower in the antibiotic group compared with the other group: ESR (mm/hr): 70 versus 85, difference of medians (DOM) = 15 mm/hr, p = 0.018; CRP (mg/L): 72 versus 130, DOM = 58 mg/L, p = 0.038; synovial WBC (cells/μL): 29,170 versus 46,900, DOM = 17,730, p = 0.022; and synovial PMN%: 88.5% versus 92.5%, DOM = 4%, p = 0.012. Furthermore, using the MSIS cutoffs, the false-negative rates of several parameters were higher in the antibiotic group; ESR: 19.2% (nine of 47) versus 6.1% (six of 99) (relative risk, 3.1; 95% confidence interval [CI], 1.2–8.3; p = 0.020); CRP: 14.9% (seven of 47) versus 2.00% (two of 100) (relative risk, 7.4; 95% CI, 1.6–34.4); PMN%: 23.1% (12 of 52) versus 9.4% (10 of 106) (relative risk, 2.4; 95% CI, 1.1–5.2; p = 0.027). Patients in the antibiotic group also had higher rates of negative cultures: 26.4% (14 of 53) versus 12.9% (14 of 108) (relative risk, 2.0; 95% CI, 1.05–3.9; p = 0.046).

Conclusions

It appears that premature antibiotic treatments are associated with lower medians of diagnostic laboratory values. Thus, and in line with the guideline recommendations of the American Academy of Orthopaedic Surgeons, patients with suspected late-PJI should not receive antibiotics until the diagnosis is reached or refuted.

Level of Evidence

Level III, diagnostic study.     

Laparoscopy-Assisted Supracervical Hysterectomy for Ovarian Cancer: Cervical Recurrence

Background and Objectives:

The purpose of our study is to evaluate the incidence of cervical recurrence after laparoscopic supracervical hysterectomy for ovarian cancer debulking or staging.

Methods:

From a prospective surgical database, we identified 51 cases of laparoscopic supracervical hysterectomy for ovarian cancer debulking or staging. No cases were excluded.

Results:

From 2009 to 2012, 51 patients were identified. The median age was 62 years (range, 32–83 years), and the median body mass index was 29 kg/m² (range, 16–41 kg/m²). Medical comorbidities were present in 40 patients (78%), and 53% had prior abdominal surgery. The median operative time was 2 hours (range, 1–3.5 hours), and the median blood loss was 200 mL (range, 50–900 mL). The median length of stay was 1 day (range, 0–12 days). The stage was I in 12 patients, II in 6, and III/IV in 33. At a median follow-up time of 1.7 years (range, 0.3–2.6 years), 20 patients (39%) had recurrence of cancer, with a median time of recurrence of 1.1 years (range, 0.3–2.3 years). All recurrences were in the abdomen or pelvis except for 1 axillary node recurrence and 1 recurrence in the distal vagina. There were no recurrences in the remaining cervical stump. No patient had a postoperative vaginal cuff infection. Among the 104 cycles of intraperitoneal chemotherapy, there was no vaginal leakage of intraperitoneal chemotherapy.

Conclusion:

Laparoscopic supracervical hysterectomy for ovarian cancer debulking or staging does not result in cervical recurrence.     

Pathomechanisms of ulnar ligament lesions of the wrist in a cadaveric distal radius fracture model

Background and purpose

Mechanisms of injury to ulnar-sided ligaments (stabilizing the distal radioulnar joint and the ulna to the carpus) associated with dorsally displaced distal radius fractures are poorly described. We investigated the injury patterns in a human cadaver fracture model.

Methods

Fresh frozen human cadaver arms were used. A dorsal open-wedge osteotomy was performed in the distal radius. In 8 specimens, pressure was applied to the palm with the wrist in dorsiflexion and ulnar-sided stabilizing structures subsequently severed. Dorsal angulation was measured on digitized radiographs. In 8 other specimens, the triangular fibrocartilage complex (TFCC) was forced into rupture by axially loading the forearm with the wrist in dorsiflexion. The ulnar side was dissected and injuries were recorded.

Results

Intact ulnar soft tissues limited the dorsal angulation of the distal radius fragment to a median of 32^o (16–34). A combination of bending and shearing of the distal radius fragment was needed to create TFCC injuries. Both palmar and dorsal injuries were observed simultaneously in 6 of 8 specimens.

Interpretation

A TFCC injury can be expected when dorsal angulation of a distal radius fracture exceeds 32^o. The extensor carpi ulnaris subsheath may be a functionally integral part of the TFCC. Both dorsal and palmar structures can tear simultaneously. These findings may have implications for reconstruction of ulnar sided soft tissue injuries.A complex of ligaments on the ulnar side of the wrist supports the stability of the ulnocarpal and the distal radioulnar (DRU) joints. Included in this are the extensor carpi ulnaris (ECU) subsheath and the triangular fibrocartilage complex (TFCC), which is further subdivided into the radioulnar ligaments (RULs), the ulnotriquetral ligament (UT), and the ulnolunate (UL) ligament (Garcia-Elias 1998, Berger 2001). Injuries to the TFCC are common in dorsally angulated fractures of the distal radius fracture (Colle''s fracture) and may adversely affect functional outcome (Lindau et al. 2000). The pathomechanics of these injuries are poorly studied, however.During wrist arthroscopy, we have observed two lesions that are often present when treating TFCC lesions associated with distal radius fractures: (1) a separation of the floor of the ECU tendon sheath from the TFCC, and (2) an injury to the foveal insertion of the TFCC into the ulna. It seems probable that there must be a limit to how much the distal radius fragment can be displaced without rupture of the TFCC or fracture of the ulna.We investigated the characteristics of a TFCC injury in a cadaveric fracture model of dorsally displaced fractures. We hypothesized that (1) a TFCC lesion can be expected at a certain degree of displacement and that (2) a rupture of the foveal insertion would begin in the palmar capsule and progress dorsally, due to the dorsal displacement of the distal radius fragment.     

How Do Different Anterior Tibial Tendon Transfer Techniques Influence Forefoot and Hindfoot Motion?

Background

Idiopathic clubfoot correction is commonly performed using the Ponseti method and is widely reported to provide reliable results. However, a relapsed deformity may occur and often is treated in children older than 2.5 years with repeat casting, followed by an anterior tibial tendon transfer. Several techniques have been described, including a whole tendon transfer using a two-incision technique or a three-incision technique, and a split transfer, but little is known regarding the biomechanical effects of these transfers on forefoot and hindfoot motion.

Questions/purpose

We used a cadaveric foot model to test the effects of three tibialis anterior tendon transfer techniques on forefoot positioning and production of hindfoot valgus.

Methods

Ten fresh-frozen cadaveric lower legs were used. We applied 150 N tension to the anterior tibial tendon, causing the ankle to dorsiflex. Three-dimensional motions of the first metatarsal, calcaneus, and talus relative to the tibia were measured in intact specimens, and then repeated after each of the three surgical techniques.

Results

Under maximum dorsiflexion, the intact specimens showed 6° (95% CI, 2.2°–9.4°) forefoot supination and less than 3° (95% CI, 0.4°–5.3°) hindfoot valgus motion. All three transfers provided increased forefoot pronation and hindfoot valgus motion compared with intact specimens: the three-incision whole transfer provided 38° (95% CI, 33°–43°; p < 0.01) forefoot pronation and 10° (95% CI, 8.5°–12°; p < 0.01) hindfoot valgus; the split transfer, 28° (95% CI, 24°–32°; p < 0.01) pronation, 9° (95% CI, 7.5°–11°; p < 0.01) valgus; and the two-incision transfer, 25° (95% CI, 20°–31°; p < 0.01) pronation, 6° (95% CI, 4.2°–7.8°; p < 0.01) valgus.

Conclusion

All three techniques may be useful and deliver varying degrees of increased forefoot pronation, with the three-incision whole transfer providing the most forefoot pronation. Changes in hindfoot motion were small.

Clinical Relevance

Our study results show that the amount of forefoot pronation varied for different transfer methods. Supple dynamic forefoot supination may be treated with a whole transfer using a two-incision technique to avoid overcorrection, while a three-incision technique or a split transfer may be useful for more resistant feet. Confirmation of these findings awaits further clinical trials.     

Results of two different surgical techniques in the treatment of advanced-stage Freiberg's disease

Background:

Freiberg''s disease is an osteochondrosis most commonly seen in adolescent women and characterized by pain, swelling and motion restriction in the second metatarsal. The early stages of this disease can be managed with semirigid orthoses, metatarsal bars and short leg walking cast. Number of operative methods are suggested which can be used depending on the pathophysiology of the disease, including abnormal biomechanics, joint congruence and degenerative process. We evaluated the outcomes of the patients with Freiberg''s disease who were treated with dorsal closing-wedge osteotomy and resection of the metatarsal head.

Patients and Methods:

16 patients (11 female, 5 male) with a mean age of 24.5 (range 13–49 years) years who underwent dorsal closing wedge osteotomy or resection of the metatarsal head were included in this retrospective study. Second metatarsal was affected in 13 and third metatarsal in three patients. According to the Smillie''s classification system, ten patients had type IV osteonecrosis and six patients had type V. The results of the patients were evaluated using the lesser metatarsophalangeal-interphalangeal (LMPI) scale.

Results:

According to the LMPI scale, the postoperative scores for the osteotomy and excision groups were 86 (range 64–100) and 72.6 (range 60–85), respectively. In the osteotomy group, mean passive flexion restriction was 18° (range 0°–35°) and mean passive extension restriction was 12° (range 0°–25°). Mean metatarsal shortening was 2.2 mm (range 2–4 mm) in the osteotomy group as opposed to 9.8 mm (range 7–14 mm) in the excision group. Significant pain relief was obtained in both groups following the surgery.

Conclusions:

The decision of performing osteotomy or resection arthroplasty in the patients with advanced-stage Freiberg''s disease should be based on the joint injury and the patients should be informed about the cosmetic problems like shortening which may arise from resection.     

Modified Dunn Procedure is Superior to In Situ Pinning for Short-term Clinical and Radiographic Improvement in Severe Stable SCFE

Background

In situ pinning is the conventional treatment for a stable slipped capital femoral epiphysis (SCFE). However, with a severe stable SCFE the residual deformity may lead to femoroacetabular impingement and articular cartilage damage. A modified Dunn subcapital realignment procedure has been developed to allow for correction at the level of the deformity while preserving the blood supply to the femoral head.

Questions/purposes

We compared children with severe stable SCFE treated with the modified Dunn procedure or in situ pinning in terms of (1) proximal femoral radiographic deformity; (2) Heyman and Herndon clinical outcome; (3) complication rate; and (4) number of reoperations performed after the initial procedure.

Methods

In this nonmatched retrospective study, 15 patients treated with the modified Dunn procedure (between 2007 and 2012) and 15 treated with in situ pinning (between 2001 and 2009) for severe but stable SCFE were followed for a mean of 2.5 years (range, 1–6 years). During the period in question, the decision regarding which procedure to use was based on the on-call surgeon’s discretion; six surgeons performed in situ pinning and three surgeons performed the modified Dunn procedure. A total of 15 other patients were treated for the same diagnosis during the study period but were lost to followup before 1 year; of those, 12 were in the in situ pinning group. Radiographs were reviewed to measure the AP and lateral alpha angles, femoral head-neck offset, and Southwick angle preoperatively and at the latest clinical visit. The Heyman and Herndon clinical outcome, complications, and subsequent hip surgeries were recorded.

Results

At latest followup, the median AP alpha angle (52°, range 41°–59° versus 76°, interquartile range [IQR]: 68°–88°; p = 0.0017), median lateral alpha angle (44°, IQR: 40°–51° versus 87°, IQR: 74°–96°; p < 0.001), median head-neck offset (7 mm, IQR: 5–9 mm versus −5, IQR: −11 to −4 mm; p < 0.001), and median Southwick angle (16°, IQR: 6°–23° versus 58°, IQR: 47°–66°; p < 0.001) revealed better deformity correction with the modified Dunn procedure compared with in situ pinning. Nine patients had good or excellent results in the modified Dunn group compared with four of 15 in the in situ pinning group (p = 0.0343; odds ratio, 5.86; 95% CI, 1.13–40.43). With the numbers available, there were no differences in the numbers of complications in each group (five versus three complications in the in situ and modified Dunn groups, respectively; p = 0.66), but there were more reoperations in the in situ pinning group (three versus seven; p = 0.0230).

Conclusions

The modified Dunn procedure results in better morphologic features of the femur, a higher rate of good and excellent Heyman and Herndon clinical outcome, a lower reoperation rate, and a similar occurrence of complications when compared with in situ pinning for treatment of severe stable SCFE.

Level of Evidence

Level III, therapeutic study.     

Alternatives to sural nerve grafts in the upper extremity

Background

The sural nerve is the most common nerve graft donor despite requiring a second operative limb and causing numbness of the lateral foot. The purposes of this study were to review our experience using nerve autografts in upper extremity nerve reconstruction and develop recommendations for donor selection.

Methods

A retrospective case series study was performed of all consecutive patients undergoing nerve grafting procedures for upper extremity nerve injuries over an 11-year period (2001–2012).

Results

Eighty-six patients received 109 nerve grafts over the study period. Mean patient age was 42.9 ± 18.3 years; 57 % were male. There were 51 median (59 %), 26 ulnar (30 %), 14 digital (13 %), 13 radial (16 %), and 3 musculocutaneous (4 %) nerve injuries repaired with 99 nerve autografts (71 from upper extremity, 28 from lower extremity). Multiple upper extremity nerve autograft donors were utilized, including the medial antebrachial cutaneous nerve (MABC), third webspace branch of median, lateral antebrachial cutaneous nerve (LABC), palmar cutaneous, and dorsal cutaneous branch of ulnar nerve. By using an upper-extremity donor, a second operative limb was avoided in 58 patients (67 %), and a second incision was avoided in 26 patients (30 %). The frequency of sural graft use declined from 40 % (n = 17/43) to 11 % (n = 7/64).

Conclusions

Our algorithm for selecting nerve graft material has evolved with our growing understanding of nerve internal topography and the drive to minimize additional incisions, maximize ease of harvest, and limit donor morbidity. This has led us away from using the sural nerve when possible and allowed us to avoid a second operative limb in two thirds of the cases.     

Anatomic reconstruction of the radioulnar ligament

Introduction

Twenty-five patients (19 males and six females) were included in the study based on: chronic symptoms of distal radioulnar joint instability, demonstrable instability on examination, MRI evidence of radioulnar ligament deficiency, and arthroscopic findings of foveal disruption of the radioulnar ligament.

Materials and Methods

Exclusion criteria were: distal radius malunion, congenital malformation of the sigmoid notch, DRUJ arthritis, and less than 24 months minimum follow-up. Mean age was 35 years old with a mean interval from injury to surgery of 5 months. Surgery began with arthroscopic confirmation of the chronic foveal detachment followed by open reconstruction of the radioulnar ligament using the palmaris longus tendon. The specific method employed three drill tunnels corresponding to the true anatomic points of attachment of the radioulnar ligament. Patients were examined post-operatively at 2 weeks, 4 weeks, 6 weeks, 12 weeks, and 6 months.

Results and Discussion

Final evaluation averaged 51 (±14) months following surgery. Measures obtained before and after treatment included: wrist range of motion, forearm range of motion, grip strength, examination findings of distal radioulnar joint instability, and Disabilities of Arm, Shoulder, and Hand (DASH) scores. Pre-operative and post-operative measures were compared using the paired Student’s t test, accepting a p value of 0.05 as statistically significant. All patients healed the reconstruction without major complications and demonstrated distal radioulnar joint stability at the 6-week examination. Mean ranges of motion, in degrees, pre-/post-operative were: wrist flexion 53 (±13)/61 (±10), wrist extension 53 (±13)/62 (±15), supination 65 (±12)/74 (±7), and pronation 66 (±11)/71 (±8). Grip strengths expressed as % contralateral pre-/post-operative were: 57 (±23)/79 (±25). The differences in these measures were not found to be statistically significant. The mean pre-/post-operative DASH scores were: 62 (±16)/7 (±3). This difference was found to be statistically significant.

Conclusion

Reconstruction of the RUL with a free palmaris longus tendon graft using the truly anatomic points of original RUL attachment at both the ulna and radius restored DRUJ stability and improved DASH scores without limiting forearm or wrist motion.     

Percutaneous Distraction Pinning for Metacarpophalangeal Joint Stabilization After Blast or Crush Injuries of the Hand

Background

Unstable, severely comminuted fractures of the metacarpophalangeal (MCP) joint are difficult to treat. Closed treatment and casting of these fractures often fail to maintain proper alignment and impede wound care where concomitant open injuries such as gunshot wounds are present. Conventional pinning or plating techniques are not feasible if extensive bone loss and comminution are present. A distraction pinning technique represents a potential alternative, but results with this approach, to our knowledge, have not been reported.

Questions/purposes

The purposes of this study were (1) to evaluate the effectiveness (defined as osseous union and joint stability) of distraction pinning for comminuted fractures involving MCP joints after gunshot or crush injuries; (2) to report the short-term results in terms of pain and function in a small group of patients who underwent MCP distraction pinning; and (3) to evaluate complications and return to work status of these patients in the short term.

Methods

We reviewed 10 patients with comminuted pilon-type fractures of the base of the proximal phalanx or metacarpal head treated with wire distraction fixation from 2005 and 2014. During that period, we used this technique to treat all patients whose fractures were deemed too comminuted for plating or pinning, and during that period, no other techniques (such as simple external fixation) were used for patients meeting those indications. The minimum followup was 6 months; eight of the 10 patients were accounted at a median of 10 months (range, 6–89 months). The median age was 47 years (range, 28–57 years), and seven of the eight were male. Kirschner wire fixation frames were removed 3.5 to 6 weeks after the index surgery when fracture consolidation was confirmed on radiography by the treating surgeon. Stability and range of motion of the MCP joint were assessed using physical examination, radiographs, and goniometer by the treating surgeon. Patients completed the Quick Disabilities of the Arm, Shoulder and Hand score at latest followup or by telephone, and complications were assessed by chart review.

Results

All fractures were healed with stable MCP joints. Eight patients reported having no pain or minimal pain of their injuries to the hand. The median finger and thumb MCP arc of motion were 80° (range, 70°–105°) and 30° (range, 0°–60°), respectively. The median Quick Disabilities of the Arm, Shoulder and Hand score was 3 (range, 0–41). One patient underwent a second surgical procedure for bone grafting and soft tissue coverage. Three patients developed pin site irritations and were treated with oral antibiotics. Six patients returned to their original job.

Conclusions

The distraction pinning technique provides reliable osseous union and joint stability of comminuted pilon-type fractures of the base of the proximal phalanx or metacarpal head, even with associated open wounds. Future studies will need to evaluate these patients at longer term followup and compare this approach with other available techniques, because arthrosis, stiffness, and progressive loss of function seem likely to occur given the severity of these injuries.

Level of Evidence

Level IV, therapeutic study.     

Indications and early to mid-term results of ulnar head replacement

IntroductionThe aim of this study was to explore the indications and show the early to mid-term results of ulnar head replacement for the treatment of pathological conditions of the distal radioulnar joint.MethodsOur study group comprised 52 patients with a mean age of 64 years who had 56 ulnar head replacements. Seven were implanted to salvage an unstable deletive procedure; the rest were for primary treatment of osteoarthritis, rheumatoid arthritis and trauma. Concomitant procedures along with the ulnar head replacement included wrist arthrodesis, joint replacement and tendon transfers.ResultsThe follow-up duration ranged from 1 year to 11 years (mean: 60 months, median: 60 months). In almost all of the patients, pain improved with a median visual analogue scale score of 2 (mean: 2.2, range: 0–8) and a median DASH (Disabilities of the Arm, Shoulder and Hand) score of 12.5 (mean: 17.9, range: 0–56). Of the 52 patients, 47 reported they would have the same procedure again.ConclusionsUlnar head replacement appears to be a reliable and effective procedure solving several pathological problems of the distal radioulnar joint. We present a large patient group with a short to medium-term follow-up duration.