Treatment preferences for trigger digit by members of the American Association for Hand Surgery

Background

Trigger digit is a common pathology encountered by hand surgeons, but there is a lack of evidence-based guidelines. We investigated the treatment preferences of hand surgeons and explored whether geographic location, type of residency training, or clinical experience is associated with differences in practice.

Methods

An online survey was distributed via email by the American Association for Hand Surgery to 615 members. The survey consisted of 17 questions related to conservative and operative management of trigger digits.

Results

One hundred thirty-nine unique responses were received (22.6 %). Geographic distribution of respondents encompassed the entire USA and was not associated with variations in practice. Of the respondents, 56.8 % were trained in orthopedic surgery while 37.4 % had plastic surgery training. In regards to duration of practice, 8.6 % were in practice for up to 5 years, 29.5 % for 6–15 years, 33.8 % for 16–25 years, and 28.1 % for more than 25 years. Notably, the great majority of respondents preferred corticosteroid injections for initial treatment. Those who were willing to give three or more injections prior to surgery were more likely to be plastic surgeons in practice for 16 years or more. A large minority of surgeons utilized splinting in their conservative management. Orthopedic surgeons were more likely to perform tenolysis during pulley release and more likely to use monitored anesthesia care.

Conclusions

Variation exists between the treatment algorithms of hand surgeons when managing a trigger digit. Some of these differences may be attributable to the type of training or the duration of clinical practice.     

Posterior acetabular arc angle of unstable posterior hip fracture–dislocation

Purpose

Posterior hip fracture–dislocation needs stability evaluation. A previous study in the normal acetabulum has shown that the coronal posterior acetabular arc angle (PAAA) could be used to assess an unstable posterior hip fracture. Our study was designed to assess PAAA of unstable posterior hip fracture–dislocation and whether posterior acetabular wall fracture involves the superior acetabular dome.

Methods

Using coronal computed tomography (CT) of the acetabulum and 3D reconstruction of the lateral pelvis, we measured coronal, vertical PAAA and posterior acetabular wall depth of 21 unstable posterior hip fracture–dislocations and of 50 % normal contralateral acetabula. Posterior acetabular wall fracture was assessed to determine whether the fracture involved the superior acetabular dome and then defined as a high or low wall fracture using vertical PAAA in reference to the centroacetabulo–greater sciatic notch line.

Results

The coronal PAAA of unstable posterior hip fracture–dislocations and of 50 % of the posterior acetabular wall of normal the contralateral acetabulum were 54.48° (9.09°) and 57.43° (5.88°) and corresponded to 15.06 (4.39) and 15.61 (2.01) mm of the posterior acetabular wall without significant difference (p > 0.05). The vertical PAAA of unstable posterior hip fracture–dislocation was 101.67° (20.44°). There were 16 high posterior acetabular wall fractures with 35.00 (16.18) vertical PAAA involving the acetabular dome and 5 low wall fractures. High posterior wall fractures resulted in four avascular necroses of the femoral head, three sciatic nerve injuries and one osteoarthritic hip.

Conclusion

Coronal and vertical PAAA of unstable posterior hip fracture–dislocations were 54.48° and 101.67°. Vertical PAAA assesses high or low posterior acetabular wall fracture by referring to the centroacetabulo–greater sciatic notch line. High posterior wall fracture seems to be the most frequent and is involved with many complications.     

The effect of minimally displaced posterior malleolar fractures on decision making in minimally displaced lateral malleolus fractures

Purpose

Despite the high incidence of cases of minimally displaced lateral or posterior malleolus ankle fractures, treatment guidelines are still an issue of controversy. The purpose of this study was to delineate treatment preferences among orthopaedic surgeons in these fractures with and without concomitant posterior malleolus fractures. We hypothesized that concomitant minimally displaced fractures of the posterior malleolus can shift treatment preference towards operative intervention.

Methods

A questionnaire-based study was conducted among orthopaedic surgeons attending the 2012 European Federation of National Associations of Orthopaedics and Traumatology Conference (EFORT) in Berlin, Germany. Treatment preferences were reported for minimally displaced lateral malleolus fractures seen on radiographs and were then compared with treatment preferences when computed tomography (CT) was added revealing a concomitant minimally displaced posterolateral fracture of the posterior malleolus.

Results

The cohort comprised 177 surgeons from all six continents. When radiographs showing a minimally displaced lateral malleolus fracture were presented, nonoperative management was indicated by 35 % (62) of participants, whereas 65 % (115) preferred operative intervention. After CT views were added showing an accompanying minimally displaced posterolateral posterior malleolus fracture, 79 % (140) suggested operative intervention and only 21 % (37) advocated nonoperative management (p = 0.03).

Conclusions

Most surgeons prefer open reduction with internal fixation for minimally displaced lateral malleolar fractures. The presence of concomitant posterior malleolus fractures in these cases shifts treatment preference further towards open reduction with internal fixation. Because the posterior malleolus fragment might not be well delineated on standard ankle radiographs, a high index of suspicion is warranted, and the use of CT should be considered in these cases.     

Treatment of carpal tunnel syndrome by members of the American Association for Hand Surgery

Background

Carpal tunnel syndrome (CTS) is the most common compressive neuropathy affecting the upper extremity, yet evidence-based guidelines for its diagnosis and treatment are lacking. We set out to expose any potential discrepancies in CTS practice attitudes based on surgeon’s academic background, residency training, clinical experience, and other factors.

Methods

This was an online survey-based study. Members of the American Association for Hand Surgery (AAHS) were sent an electronic mail request (n = 817). The online questionnaire consisted of 12 questions that queried surgeons’ approaches to the diagnosis as well as operative and non-operative management of carpal tunnel syndrome.

Results

One hundred twenty-three surgeons responded to the survey (15.1 %). The locations of surgical practices varied within the United States and beyond. Most respondents were either orthopedic or plastic surgeons. With respect to practice duration, 15.4 % had been in practice for 5 years or less, 30.9 % of the respondents had been in practice between 6 and 15 years, 30.9 % had been in practice between 16 and 25 years, and 26.8 % had been in practice for more than 25 years. The most notable interspecialty differences were related to the use of operative antibiotics and the surgical approach. Plastic surgeons were less likely to recommend antibiotic use during surgery and more likely to utilize an open extensile approach during surgical release. Younger surgeons were more likely to employ a mini-open approach for carpal tunnel release.

Conclusions

We conclude that background training and generational differences contribute to the varied approaches observed in the diagnosis and management of CTS.     

Cams and Pincer Impingement Are Distinct, Not Mixed: The Acetabular Pathomorphology of Femoroacetabular Impingement

Background

Many impinging hips are said to have a mix of features of femoral cam and an overcovered acetabulum causing pincer impingement. Correction of such a mixed picture by reduction of the cam lesion and the acetabular rim is the suggested treatment.

Questions/purposes

We therefore asked two questions: (1) Is the acetabulum in cam impingement easily distinguishable from the pincer acetabulum, or is there a group with features of both types of impingement? (2) Is version or depth of socket better able to distinguish cam from pincer impingement?

Methods

We analyzed the morphologic features of the acetabulum and rim profile of 20 normal, healthy hips, 20 with cams and 20 with pincers on CT. Pelvises were digitized, orientated to the best-fit acetabular plane, and a rim profile was plotted.

Results

Cam hips were shallower than normal hips, which in turn were shallower than pincer hips (84° ± 5° versus 87° ± 4° versus 96° ± 5°, respectively). The rim planes of cam, normal, and pincer hips had similar version (23°, 24°, 25°), but females were 4° more anteverted than males.

Conclusions

We concluded cam and pincer hips are distinct pathoanatomic entities. Cam hips are slightly shallower than normal, whereas pincers are deeper.

Clinical Relevance

Before performing surgery for cam-type femoroacetabular impingement, surgeons should consider measuring the acetabular depth. The cam acetabulum is shallower than normal and may be rendered pathologically shallow by acetabular rim resection leading to early joint failure.     

Factors associated with the success of the Rigo System Chêneau brace in treating mild to moderate adolescent idiopathic scoliosis

Background

Adolescent idiopathic scoliosis (AIS) is the most prevalent spine deformity within the pediatric population. Orthosis is the mainstay of conservative treatment for mild to moderate AIS. The Rigo System Chêneau (RSC) brace is a custom-made thoracolumbar sacral orthosis (TLSO) based on a three-dimensional correction concept. The purpose of this study was to identify factors that could predict the therapeutic success/failure of the RSC brace.

Materials and methods

A retrospective cohort study was performed on all consecutive patients according to the Scoliosis Research Society (SRS) criteria for the success of conservative treatment. Participants had a 2-year follow-up beyond the termination of brace treatment. All patients were treated with the RSC orthotic device.

Results

Ninety-three patients met the inclusion criteria. At treatment onset, their average age was 12.9 years, average Cobb angle 31.97°, Risser score 1.07, and the mean angle of thoracic rotation (ATR) was 10.2°. The mean brace treatment period was 36 months. Treatment was successful in 83.8 % of these patients (n = 79). The average final Cobb angle was 28.97°, Risser score 4.88, and ATR 8.09°. The pre-treatment factors associated with the success of applying the RSC brace were a high Risser score [odds ratio (OR) = 2.97, 95 % confidence interval [CI] 1.18–7.44; p = 0.02), a low Cobb angle (OR = 0.92, 95 % CI 0.85–0.99; p = 0.02), and low ATR (OR = 0.86, 95 % CI 0.75–0.99; p = 0.04).

Conclusions

The treatment of mild to moderate AIS with the RSC brace provides excellent clinical results. Its added benefit is enabling a three-dimensional correction of a three-dimensional deformity. Pre-treatment high Risser score, low Cobb angles, and low ATRs are associated with treatment success.

Level of evidence

Retrospective analysis, Level III.     

Minimally invasive technique for release of Dupuytren��s contracture: segmental fasciectomy through multiple transverse incisions

Background

A multitude of operative approaches have been described for treatment of Dupuytren’s contracture. A less-invasive technique of segmental fasciectomies performed through multiple small transverse incisions is presented.

Methods

Seventy-three digits in 37 patients were treated with segmental fasciectomies. The results of 34 digits in 14 patients are described with subsequent follow-up longer than 2 years.

Results

Metacarpophalangeal joint extension improved from a mean of 32.5° to 2.2°, while proximal interphalangeal joint extension improved from 22.9° to 4.1°. Patients subjectively rated their surgical outcomes as excellent or good in 91.2% of cases. No recurrence of the disease was noted, though extension of the disease to adjacent digits was observed in three patients.

Conclusions

Though this approach is technically demanding and requires the help of a skilled assistant, this preliminary study supports our contention that this less-extensive procedure allows excellent correction of contractures; results in mild postoperative pain; and permits a rapid return of finger flexion with satisfactory long-term results so far at 2-years follow-up.     

Immobilisation of extra-articular distal radius fractures (Colles type) in dorsiflexion. The functional and anatomical outcome

Background

Cast immobilisation after successful closed reduction is a standard treatment for displaced extra-articular fractures of lower end radius. The position of the wrist during immobilisation is controversial. Immobilisation in dorsiflexion prevents redisplacement after closed reduction. Our aim is to determine the effectiveness of immobilization of wrist in dorsiflexion in such cases and evaluate anatomical and functional outcome.

Materials and methods

Study included 54 patients, above 19 years of age with closed extra-articular fractures of lower end radius treated conservatively with below elbow cast application. The wrist was maintained in 15° of dorsiflexion during plaster immobilisation. At 24 weeks, functional results were evaluated with subjective symptoms and objective signs, as per modified Demerit Point Score System. Anatomical result was evaluated based on the scheme devised by Lidstrom (1959) and modified by Sarmiento et al. (1980).

Results

76% patients had Excellent to Good subjective symptoms. Out of 42 patients that had residual dorsal angulation of less than 10°, 37 had excellent to good functional outcome. 39 of the 43 patients who had loss of radial length less than 6 mm had excellent to good functional outcome. 40 out of 49 patients having loss of radial angulation less than 9° showed excellent to good functional outcome. Functional result was directly proportional to anatomical outcome.

Conclusion

Cast immobilization of extra articular fractures of lower end radius with wrist in dorsiflexion prevents re-displacement of the fragments resulting in satisfactory anatomical & functional outcome.     

Does the position of shoulder immobilization after reduced anterior glenohumeral dislocation affect coaptation of a Bankart lesion? An arthrographic comparison

Background

The position of immobilization after anterior shoulder dislocation has been a controversial topic over the past decade. We compared the effect of post-reduction immobilization, whether external rotation or internal rotation, on coaptation of the torn labrum.

Materials and methods

Twenty patients aged <40 years with primary anterior shoulder dislocation without associated fractures were randomized to post-reduction external rotation immobilization (nine patients) or internal rotation (11 patients). After 3 weeks, magnetic resonance arthrography was performed. Displacement, separation, and opening angle parameters were assessed and analyzed.

Results

Separation (1.16 ± 1.11 vs 2.43 ± 1.17 mm), displacement (1.73 ± 1.64 vs 2.28 ± 1.36 mm), and opening angle (15.00 ± 15.84 vs 27.86 ± 14.74 °) in the externally rotated group were decreased in comparison to the internally rotated group. A statistically significant difference between groups was seen only for separation (p = 0.028); p values of displacement and opening angle were 0.354 and 0.099, respectively.

Conclusion

External rotation immobilization after reduction of primary anterior shoulder dislocation could result in a decrease in anterior capsule detachment and labral reduction.

Level of evidence

Level 2.     

Deviation analysis of C2 translaminar screw placement assisted by a novel rapid prototyping drill template: a cadaveric study

Purpose

The goal of this study is to evaluate the accuracy of patient-specific CT-based rapid prototype drill templates for C2 translaminar screw insertion.

Methods

Volumetric CT scanning was performed in 32 cadaveric cervical spines. Using computer software, the authors constructed drill templates that fit onto the posterior surface of the C2 vertebrae with drill guides to match the slope of the patient’s lamina. Thirty-two physical templates were created from the computer models using a rapid prototyping machine. The drill templates were used to guide drilling of the lamina and post-operative CT images were obtained. The entry point and direction of the planned and inserted screws were measured and compared.

Results

Sixty-four C2 translaminar screws were placed without violating the cortical bone of a single lamina. The bilateral average transverse angle of intended and actual screw for C2TLS was 56.60 ± 2.22°, 56.38 ± 2.51°, 56.65 ± 2.24°, 56.39 ± 2.45°. The bilateral mean coronal angle of the planned and actual screw for C2TLS was 0°, 0°, −0.07 ± 0.32°, 0.12 ± 0.57°. The average displacement of the entry point of the superior and inferior C2TLS in the x, y, z axis was 0.27 ± 0.85, 0.49 ± 1.46, −0.28 ± 0.69, 0.43 ± 0.88, 0.38 ± 1.51, 0.23 ± 0.64 mm.

Conclusion

The small deviations seen are likely due to human error in the form of small variations in the surgical technique and use of software to design the prototype. This technology improves the safety profile of this fixation technique and should be further studied in clinical applications.     

The accuracy of digital templating: a comparison of short-stem total hip arthroplasty and conventional total hip arthroplasty

Purpose

Selection of the correct femoral stem size is crucial in total hip arthroplasty for an uncomplicated implantation and good initial stability. Pre-operative templating has been shown to be a valuable tool in predicting the correct implant size. For short-stem total hip arthroplasty (SHA), which recently is increasingly used, it is unknown if templating can be performed as reliable as conventional total hip arthroplasty (THA).

Methods

A total of 100 hip arthroplasties, 50 with SHA and 50 with THA, were templated by four orthopaedic surgeons each. The surgeons had different levels of professional experience and performed a digital template of the acetabular and femoral component on the pre-operative radiographs. The results were compared with the truly inserted implant size.

Results

For the femoral stems the average percentage of agreement (±1 size) was 89.0 % in SHA and 88.5 % in THA. There was no significant difference among surgeons in the accuracy of templating the correct stem size and no significant difference between templating SHA and THA. For the acetabular component the average percentage of agreement (±1 size) was 75.8 %. However, the more experienced surgeons showed a significant higher accuracy for templating the correct cup size than the less experienced surgeons.

Conclusion

Digital templating of SHA can predict the stem sizes as accurately as conventional THA. Therefore digital templating is also recommendable for SHA, as it helps to predict the implant size prior to surgery and thereby might help to avoid complications.     

Functional outcome of collagenase injections compared with fasciectomy in treatment of Dupuytren’s contracture

Background

This study was designed to provide comparative information on the safety and efficacy of injection with collagenase clostridium histolyticum (CCH) and fasciectomy for patients with Dupuytren’s contracture (DC).

Methods

A single-center, retrospective, observational, longitudinal chart review was conducted of 25 patients treated with CCH injections and 21 patients undergoing fasciectomy. Patients were assessed at 1 week, monthly for 3 months and then yearly for a minimum of 2 years after treatment for changes in contracture and range of motion, time to return to work/normal activities, patient satisfaction, and Disabilities of Arm, Shoulder and Hand (DASH) score.

Results

Post-procedure follow-up averaged 32 months for the injection group compared with 39 months for fasciectomy group. For the CCH group, the mean postinjection contracture was 3.6° for the metacarpophalangeal and 17.5° for the proximal interphalangeal joints compared with 3.7° and 8.1° in the fasciectomy group, respectively. Patients treated with injections returned to normal activities after a mean of 1.9 days compared with 37.4 days for fasciectomy patients (p < 0.0001). DASH scores for 13 CCH and 15 fasciectomy patients were obtained. The mean DASH score was significantly lower in the injection group in the first 3 months (p < 0.01). At the 2-year follow-up visit, patients were satisfied with their outcomes following either treatment (92 % and 96 % of CCH and fasciectomy patients, respectively).

Conclusion

CCH injections are safe and effective and may be a viable alternative to fasciectomy for treating DC. It also allows earlier return to work and daily activities.     

The fate of B?hler’s angle in conservatively-treated displaced intra-articular calcaneal fractures

Purpose

Although the predictive value of Böhler’s angle on outcome remains subject of debate, the initial angle at the time of trauma still guides treatment. Changes in Böhler’s angle during follow-up are frequently reported following surgical treatment of displaced intra-articular calcaneal fractures (DIACF). The aim of the present study was to determine the changes in Böhler’s angle as a measure of secondary fracture displacement following conservative management of DIACF.

Methods

Thirty-eight patients with a total of 44 displaced intra-articular calcaneal fractures treated conservatively with a minimum of two lateral radiographs during follow-up were analysed. Böhler’s angle at different follow-up times was measured by three observers. The change in angle was compared with the angle at trauma, and influence of trauma mechanism and common calcaneal fracture classifications were determined.

Results

The results showed a significant decline over time of the Böhler’s angle in conservatively-treated patients of more than 11° on average at a mean follow-up of 29.2 weeks. This decrease was not related to gender, the initial angle, or the Essex-Lopresti or Sanders classification. A statistically significantly higher decrease was detected in high energetic trauma compared with low energetic trauma.

Conclusion

The conservative treatment of displaced intra-articular calcaneal fractures is still a viable option, yet a significant secondary displacement in time should be taken into account, as reflected in a decrease of Böhler’s angle of 11° up to one year following trauma.     

Radial head arthroplasty using a metatarsal osteochondral autograft

Purpose

Treatment of comminuted fractures of the radial head is controversial, and considerable effort has been made to restore optimal function of the elbows, either by surgical reconstruction or prosthetic replacement. This report presents our experiences in treatment of unreconstructable radial head or neck fractures using osteochondral autografts harvested from the base of the second metatarsal bones.

Methods

Five patients with radial head and one with a radial neck fracture underwent treatment with osteochondral autografts. After excision of the unreconstructable radial head, the second metatarsal base was harvested and transplanted to the radius using the intramedullary nailing technique.

Results

The reconstructed elbows were examined clinically and radiographically for a mean period of 44.8 months (range, 24–72 months). At the last follow-up, in flexion-extension, the mean elbow mobility was 130°/10°. In supination-pronation, the mean elbow mobility was 73.3°/66.7°, with a mean loss of supination of 19.2° and loss of pronation of 12.5°. Grip strength was 91%, compared with the contralateral limb. The mean Mayo Elbow Performance Score was 94.2. The mean score of AOFAS rating system to the lesser toe was 93.7 points.

Conclusion

Radial head arthroplasty with an osteochondral autograft from the second metatarsal base appears to be an effective alternative for treatment of unreconstructable radial head fractures. A larger group of patients and a longer follow-up period will be required in order to ease concerns regarding the donor site; however, none of the patients who underwent this procedure showed any complications during follow-up.     

Examining the efficacy and maintenance of contracture correction after collagenase clostridium histolyticum treatment for Dupuytren’s disease

Background

This study examined the efficacy, complications, and contracture recurrence in patients who received injectable collagenase clostridium histolyticum (CCH) for Dupuytren’s-induced metacarpophalangeal (MP) and proximal interphalangeal (PIP) joint contractures.

Methods

A retrospective chart review at one center compared the degree of MP and PIP joint contracture pre-injection, post-cord rupture, and at final follow-up after a minimum duration of 6 months. Recurrence was defined as a 20 ° or greater increase in contracture above the minimum value achieved.

Results

Of 102 eligible patients, 48 patients (47 %) (31 males, 17 females) were available for review. 53 digits and 64 joints (46 MP joints and 18 PIP joints) were studied. The mean patient age was 66 years (range, 48–87 years) and mean follow-up duration was 15 months (range, 6 to 25 months). The mean MP joint contracture was 51 ± 20 ° at baseline, 4 ± 8 ° post-cord rupture, and 9 ± 15 ° at latest follow-up. The mean PIP joint contracture was 39 ± 23 ° at baseline, 14 ± 14 ° at cord rupture, and 29 ± 20 ° at latest follow-up. Of the 46 MP joints and 18 PIP joints, 11 MP (24 %) and 7 (39 %) PIP joints met the recurrence criteria. Of 102 patients, 1 patient had a small finger flexor tendon rupture.

Conclusions

Despite the dramatic initial reduction in contracture, recurrence developed in a high proportion of patients over the study period. While initially effective, CCH may not provide durable contracture reduction. However, CCH remains a viable nonsurgical treatment for Dupuytren’s disease.     

Etanercept treatment enhances clinical and neuroelectrophysiological recovery in partial spinal cord injury

Purpose

To investigate the effect of an anti-TNF-α agent (etanercept) on recovery processes in a partial spinal cord injury (SCI) model using clinical and electrophysiological tests.

Methods

Twenty-four New Zealand rabbits were divided into three groups: group 1 [SCI + 2 ml saline intramuscular (i.m.), n = 8], group 2 (SCI + 2.5 mg/kg etanercept, i.m., 2–4 h after SCI, n = 8) and group 3 (SCI + 2.5 mg/kg etanercept, i.m., 12–24 h after SCI, n = 8). Rabbits were evaluated before SCI, immediately after SCI, 1 week after, and 2 weeks after SCI, clinically by Tarlov scale and electrophysiologically by SEP.

Results

Tarlov scores of groups 2 and 3 were significantly better than group 1, 2 weeks after SCI. SEP recovery was significantly better in groups 2 and 3 than group 1, 2 weeks after SCI.

Conclusions

These results show that blocking TNF-α mediated inflammation pathway by an anti-TNF-α agent enhances clinical and electrophysiological recovery processes in partial SCI model.     

What Are the Biomechanical Effects of Half-pin and Fine-wire Configurations on Fracture Site Movement in Circular Frames?

Background

Fine-wire circular frame (Ilizarov) fixators are hypothesized to generate favorable biomechanical conditions for fracture healing, allowing axial micromotion while limiting interfragmentary shear. Use of half-pins increases fixation options and may improve patient comfort by reducing muscle irritation, but they are thought to induce interfragmentary shear, converting beam-to-cantilever loading. Little evidence exists regarding the magnitude and type of strain in such constructs during weightbearing.

Questions/purposes

This biomechanical study was designed to investigate the levels of interfragmentary strain occurring during physiologic loading of an Ilizarov frame and the effect on this of substituting half-pins for fine-wires.

Methods

The “control” construct was comprised of a four-ring all fine-wire construct with plain wires at 90°-crossing angles in an entirely unstable acrylic pipe synthetic fracture model. Various configurations, substituting half-pins for wires, were tested under levels of axial compression, cantilever bending, and rotational torque simulating loading during gait. In total three frames were tested for each of five constructs, from all fine-wire to all half-pin.

Results

Substitution of half-pins for wires was associated with increased overall construct rigidity and reduced planar interfragmentary motion, most markedly between all-wire and all-pin frames (axial: 5.9 mm ± 0.7 vs 4.2 mm ± 0.1, mean difference, 1.7 mm, 95% CI, 0.8–2.6 mm, p < 0.001; torsional: 1.4% ± 0.1 vs 1.1% ± 0.0 rotational shear, mean difference, 0.3%, 95% CI, 0.1%–0.5%, p = 0.011; bending: 7.5° ± 0.1 vs 3.4° ± 0.1, mean difference, −4.1°, 95% CI, −4.4° to −3.8°, p < 0.001). Although greater transverse shear strain was observed during axial loading (0.4% ± 0.2 vs 1.9% ± 0.1, mean difference, 1.4%, 95% CI, 1.0%–1.9%, p < 0.001), this increase is unlikely to be of clinical relevance given the current body of evidence showing bone healing under shear strains of up to 25%. The greatest transverse shear was observed under bending loads in all fine-wire frames, approaching 30% (29% ± 1.9). This was reduced to 8% (±0.2) by incorporation of sagittal plane half-pins and 7% (±0.2) in all half-pin frames (mean difference, −13.2% and −14.0%, 95% CI, −16.6% to 9.7% and −17.5% to −10.6%, both p < 0.001).

Conclusions

Appropriate use of half-pins may reduce levels of shear strain on physiologic loading of circular frames without otherwise altering the fracture site mechanical environment at levels likely to be clinically important. Given the limitations of a biomechanical study using a symmetric and uniform synthetic bone model, further clinical studies are needed to confirm these conclusions in vivo.

Clinical Relevance

The findings of this study add to the overall understanding of the mechanics of circular frame fixation and, if replicated in the clinical setting, may be applied to the preoperative planning of frame treatment, particularly in unstable fractures or bone transport where control of shear strain is a priority.     

Pelvic Flexion Measurement From Lateral Projection Radiographs is Clinically Reliable

Background

Pelvic flexion affects orientation of the acetabular cup; however, pelvic position is not static in daily activities. During THA it is difficult to know the degree of pelvic flexion with the patient in the lateral position and that position is static. However, surgeons need to appropriately determine pelvic tilt to properly insert the acetabular component.

Questions/purposes

We investigated the reliability of pelvic flexion angle that was measured by manually identifying the location of the pubic symphysis and bilateral anterior superior iliac spines using synthesized lateral radiographs.

Methods

We synthesized 49 lateral radiographs based on CT data. Each of the 49 radiographs had a unique position: 7° of varying lateral tilt and rotation in each of seven selected pelvic flexion angles. The pelvic flexion angle was measured three times by three independent observers in each position and determined the accuracy (based on the true value from the reconstructions) and reliability of the measures.

Results

The measurement error was 0.1° (range, −4.8° to 4.0°). There was a tendency for errors when the pelvic flexion angle was 0° or ± 5°; the errors were less when the pelvic flexion angle was ± 10° or ± 20°. Lateral tilt was associated with greater error than rotation. The intraclass correlation coefficient (ICC) of the average value was 0.967. For one observer, more than two measurements are necessary for the ICC to be greater than 0.8, and only one measurement was needed for two of the three observers.

Conclusions

Our data suggest measurement of pelvic flexion angle using lateral radiographs is reliable. We recommend the measurement be performed once by two observers for better reliability.     

Musculoskeletal manifestations of neonatal nonketotic hyperglycinemia

Purpose

Neonatal nonketotic hyperglycinemia is an autosomal recessive inborn disorder of glycine metabolism in which large quantities of glycine accumulate in all body tissues. It is characterized by a progressive lethargy, hypotonia, myoclonic jerks, and early death secondary to respiratory problems. As a result of early diagnosis and treatment protocols, more patients survive the critical neonatal period with profound mental retardation, delayed developmental milestones, seizures, and spasticity. There are no reports about the orthopaedic manifestations of neonatal nonketotic hyperglycinemia. The purpose of this study is to evaluate the musculoskeletal findings of neonatal nonketotic hyperglycinemia.

Methods

This is a retrospective IRB-approved study of all patients in our Orthopaedic and Genetics Clinics with the diagnosis of neonatal nonketotic hyperglycinemia during a 10-year period. Demographic, clinical, and imaging data were analyzed.

Results

Twelve patients with neonatal nonketotic hyperglycinemia were evaluated, with a mean age of 7 years and 2 months (range: 5 months to 21 years). Seven were male and five were female. Eleven patients (92 %) have evidence of progressive early-onset neuromuscular scoliosis with a mean Cobb angle of 55° (range: 30–95°). Five children (42 %) presented evidence of progressive hip dislocation secondary to spasticity. All the patients have severe multiple joint contractures.

Conclusion

Neonatal nonketotic hyperglycinemia is a rare metabolic disorder presented in the past as a lethal condition. Recent advances in early diagnosis and neonatal care improve overall outcome. As pediatric orthopaedic surgeons, we need to establish treatment based on update information of the disease and probability to improve quality of life.     

Posterior acetabular arc angle of the femoral head assesses instability of posterior fracture-dislocation of the hip

Purpose

Unstable posterior fracture-dislocation of the hip is determined by the wall defect or acetabular fracture index. The unstable hip is a result of inadequate posterior acetabular coverage of the femoral head from the posterior acetabular wall fracture. In order to measure total posterior acetabular coverage of the femoral head and avoid using the contralateral acetabulum as a calculation reference, the posterior acetabular arc angle of the femoral head was measured to assess stability of posterior fracture-dislocation of the hip.

Methods

Using coronal computed tomography (CT) scan of the normal contralateral acetabulum at the level of the widest acetabular diameter and thinnest medial wall of 60 acetabular fractures, posterior acetabular arc angles of the femoral head in intact, 20 % and 50 % defects of posterior acetabular walls were measured. The angles were measured from the acetabular centre to the thinnest medial wall and to the top, inner cortex of 80 % and 50 % posterior acetabular walls.

Results

Average intact, 80 % and 50 % posterior acetabular walls were 33.82 ± 4.30, 26.88 ± 3.33 and 16.91 ± 2.15 mm which corresponded to 92.25 ± 11.34, 77.42 ± 10.04 and 50.63 ± 6.58° of posterior acetabular arc angles of the femoral head. The intraclass correlation coefficient (ICC) of the measurements including correlation of conversion of posterior acetabular wall depths to posterior acetabular arc angles of the femoral head were more than 0.82 and 0.89.

Conclusions

The measurement technique of posterior acetabular arc angle of the femoral head has strong reliability. Therefore, stable or unstable posterior fracture-dislocation of the hip can be determined in terms of more than 77 degrees or less than 50 degrees of posterior acetabular arc angles of the femoral head instead of less than 20 % or more than 50 % posterior acetabular wall defect.