Latissimus Dorsi and Teres Major Transfer With Reverse Shoulder Arthroplasty Restores Active Motion and Reduces Pain for Posterosuperior Cuff Dysfunction

Background

In patients with rotator cuff dysfunction, reverse shoulder arthroplasty can restore active forward flexion, but it does not provide a solution for the lack of active external rotation because of infraspinatus and the teres minor dysfunction. A modified L’Episcopo procedure can be performed in the same setting wherein the latissimus dorsi and teres major tendons are transferred to the lateral aspect of proximal humerus in an attempt to restore active external rotation.

Questions/purposes

(1) Do latissimus dorsi and teres major tendon transfers with reverse shoulder arthroplasty improve external rotation function in patients with posterosuperior rotator cuff dysfunction? (2) Do patients experience less pain and have improved outcome scores after surgery? (3) What are the complications associated with reverse shoulder arthroplasty with latissimus dorsi and teres major transfer?

Methods

Between 2007 and 2010, we treated all patients undergoing shoulder arthroplasty who had a profound external rotation lag sign and advanced fatty degeneration of the posterosuperior rotator cuff (infraspinatus plus teres minor) with this approach. A total of 21 patients (mean age 66 years; range, 58–82 years) were treated this way and followed for a minimum of 2 years (range, 26–81 months); none was lost to followup, and all have been seen in the last 5 years. We compared pre- and postoperative ranges of motion, pain, and functional status; scores were drawn from chart review. We also categorized major and minor complications.

Results

Active forward flexion improved from 56° ± 36° to 120° ± 38° (mean difference: 64° [95% confidence interval {CI}, 45°–83°], p < 0.001). Active external rotation with the arm adducted improved from 6° ± 16° to 38° ± 14° (mean difference: 30° [95% CI, 21°–39°], p < 0.001); active external rotation with the arm abducted improved from 19° ± 25° to 74° ± 22° (mean difference: 44° [95% CI, 22°–65°], p < 0.001). Pain visual analog score improved from 8.4 ± 2.3 to 1.7 ± 2.1 (mean difference: −6.9 [95% CI, −8.7 to −5.2], p < 0.001), and Single Assessment Numeric Evaluation score improved from 28% ± 21% to 80% ± 24% (mean difference: 46% [95% CI, 28%–64%], p < 0.001). There were six major complications, five of which were treated operatively. Overall, three patients’ latissimus and teres major transfer failed based on persistent lack of external rotation.

Conclusions

In patients with posterior and superior cuff deficiency, reverse shoulder arthroplasty combined with latissimus dorsi and teres major transfer through a single deltopectoral incision can reliably increase active forward flexion and external rotation. Patients experience pain relief and functional improvement but have a high rate of complications; therefore, we recommend the procedure be limited to patients indicated for reverse who have profound external rotation loss and a high grade of infraspinatus/teres minor fatty atrophy.

Level of Evidence

Level IV, therapeutic study.     

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.     

Collateral Ligament Laxity in Knees: What Is Normal?

Background

Proper alignment and balancing of soft tissues of the knee are important goals for TKA. Despite standardized techniques, there is no consensus regarding the optimum amount of collateral ligament laxity one should leave at the end of the TKA.

Questions/purposes

I asked (1) what is the collateral laxity in young healthy volunteers, and (2) is there a difference in collateral laxity between males and females.

Methods

The femorotibial mechanical angle (FTMA) was measured in 314 knees in healthy volunteers aged 19 to 35 years. Subjects with a history of pain, malalignment, dysplasia, or trauma were excluded. Twenty-five knees were excluded because the hip center could not be acquired, and 22 were excluded because of a history of pain and trauma, leaving 267 knees for inclusion in the study. Of these, 155 were from men and 112 were from women. A validated method using a computer navigation system was used to obtain the measurements. A 10-Nm torque was used to stress the knee in varus and valgus at 0° extension and 15° flexion. An independent t-test and ANOVA were applied to the data to calculate any significant difference between groups (p < 0.05).

Results

The mean (SD) unstressed supine FTMA was varus of 1.2° (SD, 4°) in 0° extension and varus of 1.2° (SD, 4.4°) in 15° flexion (p = 0.88). On varus torque of 10 Nm, the supine FTMA changed by a mean of 3.1° (SD, 2°) (95% CI, 2.4°–3.8°; p < 0.001) in 0° extension and 6.9° (SD, 2.6°) (95% CI, 6.2°–7.7°; p < 0.001) in 15° flexion. On valgus torque of 10 Nm, the FTMA changed by a mean of 4.6° (SD, 2.2°) (95% CI, 3.9°–5.3°; p < 0.001) in 0° extension and 7.9° (SD, 3.4°) (95% CI, 7.1°–8.7°; p < 0.001) in 15° flexion. The mean unstressed FTMA in 0° extension was varus of 1.7° (SD, 4°) in men and 0.4° (SD, 3.9°) in women (p = 0.01). Differences in collateral ligament laxity were seen between men and women (p < 0.001 for valgus torque and 0.035 for varus torque in 15° flexion). With valgus torque at 0° flexion, the supine FTMA change was valgus of 4.2° (SD, 2.0°) for men and 5.0° (SD, 2.4°) for women, while at 15° flexion the FTMA change was valgus 7.6° (SD, 3.6°) for men and 8.3° (SD, 3.2°) for women With varus torque at 0° flexion, additional varus was −3.0° (SD, 1.8°) for men and −3.3° (SD, 2.2°) for women, while at 15° flexion, varus was −7.0° SD, (2.5°) for men and −6.9° (SD, 2.8°) for women.

Conclusions

The collateral laxity in young healthy volunteers was quantified in this study. The collateral ligament laxity is variable in different persons. In addition, ligaments in women are more lax than in men in valgus stress.

Clinical Relevance

This study was conducted on young, healthy knees. Whether the findings are applicable to arthritic knees and replaced knees needs additional evaluation. However the findings provide a baseline from which to work in the evaluation of arthritic knees and in the case of TKA.     

Radiographic quantification of dynamic hip screw migration

Purpose

This study aimed to propose a technique to quantify dynamic hip screw (DHS®) migration on serial anteroposterior (AP) radiographs by accounting for femoral rotation and flexion.

Methods

Femoral rotation and flexion were estimated using radiographic projections of the DHS® plate thickness and length, respectively. The method accuracy was evaluated using a synthetic femur fixed with a DHS® and positioned at pre-defined rotation and flexion settings. Standardised measurements of DHS® migration were trigonometrically adjusted for femoral rotation and flexion, and compared with unadjusted estimates in 34 patients.

Results

The mean difference between the estimated and true femoral rotation and flexion values was 1.3° (95 % CI 0.9–1.7°) and −3.0° (95 % CI – 4.2° to −1.9°), respectively. Adjusted measurements of DHS® migration were significantly larger than unadjusted measurements (p = 0.045).

Conclusion

The presented method allows quantification of DHS® migration with adequate bias correction due to femoral rotation and flexion.

Electronic supplementary material

The online version of this article (doi:10.1007/s00264-013-2146-4) contains supplementary material, which is available to authorised users.     

Does Native Combined Anteversion Influence Pain Onset in Patients With Dysplastic Hips?

Background

Combined anteversion is the sum of femoral and acetabular anteversion and represents their morphological relationship in the axial plane. Few studies have investigated the native combined anteversion in patients with symptomatic dysplastic hips.

Questions/purposes

We hypothesized the following: (1) dysplastic hips have two distinct populations, which differ from each other and from normal hips in their combined anteversion; and (2) these populations differ clinically in terms of correlation between age of onset of symptoms and amount of anteversion.

Methods

We measured radiographic parameters by CT of 100 dysplastic hips in 76 patients who were symptomatic enough to undergo periacetabular osteotomy and of 50 normal hips in 44 patients who had CT scans as part of preparation for computer-navigated TKAs; these patients had no visible hip arthritis or dysplasia and no hip symptoms. Dysplastic hips were divided into the anteversion (83 hips) and retroversion groups (17 hips) based on acetabular version. Age at pain onset was determined from their medical charts.

Results

Combined anteversion in the anteversion group was greater than that in the retroversion and control groups: 47° ± 12°, 30° ± 16°, and 36° ± 9°, respectively. In the anteversion group, combined anteversion (r = −0.49; 95% confidence interval [CI], −0.66 to −0.27; p < 0.001) and femoral anteversion (r = −0.41; 95% CI, −0.60 to −0.19; p < 0.001) were associated with an earlier age at pain onset; however, no such relationships were observed in the retroversion group. After controlling for relevant potential confounding variables, we found that combined anteversion (hazard ratio [HR], 1.04; 95% CI, 1.01–1.07; p = 0.006) and Sharp angle (HR, 1.10; 95% CI, 1.02–1.17; p = 0.008) were associated with an earlier age of pain onset in the anteversion group.

Conclusions

These results suggest that not only lateral coverage of the femoral head, but also axial joint morphology is important for the development of pain in the anteversion group. Optimal combined anteversion should be considered during periacetabular osteotomy.

Level of Evidence

Level IV, prognostic study.     

Lengthening With External Fixation Is Effective in Congenital Femoral Deficiency

Background

Treatment of congenital femoral deficiency is a complex, multistage protocol and a variety of strategies have been devised to address joint instability, limb length inequality, and deformities. Despite being an important part of the algorithmic approach to the overall treatment of patients with congenital femoral deficiency, a reproducible, safe, and functional treatment for femoral length discrepancy in patients with mild and moderate congenital femoral deficiency has not been reported.

Questions/purposes

(1) Does femoral lengthening by means of distraction osteogenesis, using a monolateral external fixator, result in effective lengthening without loss of hip or knee range of motion? (2) Does femoral lengthening cause an inhibition of femoral growth in patients with congenital femoral deficiency? (3) Do patients/families report satisfactory functional and emotional outcomes after undergoing femoral lengthening? (4) What proportion of patients develops complications after femoral lengthening with this technique?

Methods

Between 2005 and 2009, we evaluated 38 patients for femoral length discrepancy secondary to unilateral congenital femoral deficiency. Thirty-two patients completed treatment with distraction osteogenesis using a monolateral external fixator; general indications for this approach were congenital femoral deficiency Paley Types 1a, 1b, or 2a that had not previously undergone lengthening and had stable hip and knee joints. Of the 32 patients that completed treatment, 30 (94%) were available at a minimum of 2 years (mean, 3 years; range, 2–4.5 years) and were evaluated in this retrospective study. Preoperative and postoperative radiographic analysis, physiotherapy data, patient-based outcomes scores, and complications were reviewed for all eligible patients. Growth inhibition was measured using serial radiographs over the 2-year followup with the unaffected limb considered the norm. Functional and emotional outcomes were reported by adolescent patients or parents of younger children using the Pediatric Orthopaedic Society of North America Pediatric Outcomes Data Collection Instruments (PODCI), a validated patient-based outcomes measure.

Results

The mean distal femoral lengthening was 6 cm (SD ± 2 cm; range, 1.6–9 cm), for a mean percent of femoral length discrepancy correction of 112% (SD ± 55%; range, 15%–215%). Comparison of patient preoperative with postoperative mean hip and knee flexion and extension showed no difference with the numbers available (hip flexion: p = 0.219, mean difference of −5, 95% confidence interval [CI], 10, SD = 20; hip extension: p = 0.423, mean difference of −1, 95% CI, 2, SD = 5; knee flexion: mean difference of −7°, SD ± 29°, CI, 15, p = 0.467; knee extension: mean difference of −1°, SD ± 9°, CI, 4, p = 0.757). A comparison of the mean preoperative inhibition of 41% (range, −38% to 300%; SD ± 72; 95% CI, 29%) with the mean postoperative inhibition of 16% (range, −242% to 100%; SD ± 61%; 95% CI, 25%) for a mean postoperative stimulation of 25% (p = 0.055, SD ± 90%; 95% CI, 36%). In all six PODCI categories surveyed, patients had favorable standardized and normative scores, but patients who underwent femoral lengthening greater than 6 cm had both lower global functioning scores (90, SD ± 10 versus 96, SD ± 3, p = 0.043) and worse pain/comfort scores (79, SD ± 25 versus 96, SD ± 7, p = 0.029), and patients who had mean percent femoral lengthening greater than 25% of initial femur length had worse pain/comfort scores (79, SD ± 23 versus 97, SD ± 4, p = 0.012) with similar global functioning scores (90, SD ± 9 versus 96, SD ± 3, p = 0.058). The total number of postsurgical complications was 30 in 60 planned surgical procedures (50%).

Conclusions

Our study results support the use of the described surgical technique for femoral lengthening in treating patients with congenital femoral deficiency. Additional studies are needed both to follow long-term patient-reported outcome measures, especially after a second or third lengthening, and to determine the effect of serial lengthening on the stimulation or inhibition of growth and rate of complications.

Level of Evidence

Level IV, therapeutic study.     

Does Race Affect Outcomes in Total Joint Arthroplasty?

Background

Several studies suggest worse surgical outcomes among racial/ethnic minorities. There is a paucity of research on preoperative and postoperative pain, general health, and disease-specific measures in which race is the main subject of investigation; furthermore, the results are not conclusive.

Questions/purposes

(1) Do black patients have more severe or more frequent preoperative pain, well-being, general health, and disease-specific scores when compared with white patients? (2) Are there differences between black patients and white patients after hip or knee arthroplasty on those same measures?

Methods

In this retrospective study, we used an institutional arthroplasty registry to analyze data on 2010 primary arthroplasties (1446 knees and 564 hips) performed by one surgeon at a single institution. Cases from patients self-identifying as black (n = 105) and white (n = 1905) were compared (controlling for confounders, including age and ethnicity) on the following preoperative and postoperative patient-oriented outcomes: pain intensity/frequency as measured by a visual analog scale (VAS), Quality of Well-Being (QWB-7), SF-36, and WOMAC scores. T-tests, chi square, and multivariate analysis of covariance were used. Alpha was set at 0.05. Postoperative analysis was performed only on those cases that had a minimum followup of 1 year (mean, 3.5 years; range, 1–9 years). Of the 2010 arthroplasties, 37% (39 of 105) of those cases performed in black patients and 64% (1219 of 1905) of those performed in white patients were included in the final postoperative model (multivariate analysis of covariance).

Results

Black patients had more severe preoperative pain intensity (VAS: 8 ± 1.8 versus 8 ± 2.0, mean difference = 0.76 [95% confidence interval {CI}, 0.34–1.1], p < 0.001). Black patients also had worse well-being scores (QWB-7: 0.527 ± 0.04 versus 0.532 ± 0.05, mean difference = −0.01 [CI, −0.02 to 0.00], p = 0.037). Postoperatively, pain intensity (VAS: 1 ± 3.1 versus 1 ± 1.8, mean difference= 0.8 [CI, 0.19–1.4], p= 0.010) and (QWB-7: 0.579 ± 0.09 versus 0.607 ± 0.11, mean difference= −0.049 [CI, −0.08 to −0.01], p = 0.008) were different but without clinical significance.

Conclusions

Black patients underwent surgery earlier in life and with different preoperative diagnoses when compared with white patients. Black patients had worse preoperative baseline pain, well-being, general health, and disease-specific scores as well as worse postoperative scores. However, these differences were very narrow and without clinical significance. Notwithstanding, the relations of race with outcomes remain complex. Further investigations to recognize disparities and minimize or address them are warranted.

Level of Evidence

Level III, prognostic study.     

Sex Differences in Arm Muscle Fatigability With Cognitive Demand in Older Adults

Background

Muscle fatigability can increase when a stressful, cognitively demanding task is imposed during a low-force fatiguing contraction with the arm muscles, especially in women. Whether this occurs among older adults (> 60 years) is currently unknown.

Questions/purposes

We aimed to determine if higher cognitive demands, stratified by sex, increased fatigability in older adults (> 60 years). Secondarily, we assessed if varying cognitive demand resulted in decreased steadiness and was explained by anxiety or cortisol levels.

Methods

Seventeen older women (70 ± 6 years) and 13 older men (71 ± 5 years) performed a sustained, isometric, fatiguing contraction at 20% of maximal voluntary contraction until task failure during three sessions: high cognitive demand (high CD = mental subtraction by 13); low cognitive demand (low CD = mental subtraction by 1); and control (no subtraction).

Results

Fatigability was greater when high and low CD were performed during the fatiguing contraction for the women but not for the men. In women, time to failure with high CD was 16 ± 8 minutes and with low CD was 17 ± 4 minutes, both of which were shorter than time to failure in control contractions (21 ± 7 minutes; high CD mean difference: 5 minutes [95% confidence interval {CI}, 0.78–9.89], p = 0.02; low CD mean difference: 4 minutes [95% CI, 0.57–7.31], p = 0.03). However, in men, no differences were detected in time to failure with cognitive demand (control: 13 ± 5 minutes; high CD mean difference: −0.09 minutes [95% CI, −2.8 to 2.7], p = 1.00; low CD mean difference: 0.75 minutes [95% CI, −1.1 to 2.6], p = 0.85). Steadiness decreased (force fluctuations increased) more during high CD than control. Elevated anxiety, mean arterial pressure, and salivary cortisol levels in both men and women did not explain the greater fatigability during high CD.

Conclusions

Older women but not men showed marked increases in fatigability when low or high CD was imposed during sustained static contractions with the elbow flexor muscles and contrasts with previous findings for the lower limb. Steadiness decreased in both sexes when high CD was imposed.

Clinical Relevance

Older women are susceptible to greater fatigability of the upper limb with heightened mental activity during sustained postural contractions, which are the foundation of many work-related tasks.     

Reliability of the sit-up test in individuals with spinal cord injury

Objective

To determine the day-to-day reliability of blood pressure responses during a sit-up test in individuals with a traumatic spinal cord injury (SCI).

Design

Within-subject, repeated measures design.

Setting

Community outpatient assessments at a research laboratory at the University of British Columbia.

Participants

Five men and three women with traumatic SCI (age: 31 ± 6 years; C4-T11; American Spinal Injury Association Impairment Scale A-B; 1–17 years post-injury).

Outcome measure

Maximum change in systolic (ΔSBP) and diastolic (ΔDBP) blood pressure upon passively moving from a supine to seated position.

Results

The average values for ΔSBP were –11 ± 13 mmHg (range –38 to 3 mmHg) for visit 1, and −12 ± 8 mmHg (range −26 to −1 mmHg) for visit 2. The average values for ΔDBP were −9 ± 8 mmHg (range -21 to 0 mmHg) for visit 1, and –13 ± 8 mmHg (range –29 to –3 mmHg) for visit 2. The ΔSBP demonstrated substantial reliability with an intraclass correlation coefficient of 0.79 (P = 0.006; 95% CI 0.250–0.953), while the ΔDBP demonstrated almost perfect reliability with an intraclass correlation coefficient of 0.92 (P < 0.001; 95% CI 0.645–0.983). The smallest detectable differences in ΔSBP and ΔDBP were 7 mmHg and 6 mmHg, respectively.

Conclusion

Blood pressure responses to the sit-up test are reliable in individuals with SCI, which supports its implementation as a practical bedside assessment for orthostatic hypotension in this at risk population.     

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.     

Can High-friction Intraannular Material Increase Screw Pullout Strength in Osteoporotic Bone?

Background

Osteoporotic bone brings unique challenges to orthopaedic surgery, including a higher likelihood of problematic screw stripping in cancellous bone. Currently, there are limited options to satisfactorily repair stripped screws. Additionally, nonstripped screws hold with less purchase in osteoporotic bone.

Questions/purposes

This study attempts to answer the following questions: (1) Does high-friction intraannular (HFIA) augmentation increase pullout strength in osteoporotic and in severely osteoporotic bone; and (2) can HFIA repair stripped bone thread in osteoporotic and severely osteoporotic bone?

Methods

We measured screw pullout strength using a synthetic bone model in three groups: (1) predrilled nonstripped control holes as controls; (2) predrilled nonstripped augmented with HFIA; and (3) predrilled stripped holes repaired with HFIA. We tested this in osteoporotic and severely osteoporotic synthetic bone for a total of six test groups. We measured screw pullout force using an electromechanical tensile-testing machine comparing pullout force between the test groups and controls.

Results

HFIA augmentation did not increase pullout force compared with the control group in the osteoporotic bone model (489 ± 175 versus 607 ± 76, respectively; effect size = 0.94 [95% confidence interval {CI}, −1.75 to 0.08], p = 0.06). However, in severely osteoporotic cancellous bone that was augmented, the HFIA material generated more pullout force than the control (51 ± 18 versus 35 ± 16, respectively; effect size = 0.94 [95% CI, −0.02 to 1.82], p = 0.05). In stripped holes, HFIA partially restored pullout strength but remained weaker than controls in both osteoporotic and severely osteoporotic bone models (osteoporotic: 320 ± 59 versus 607 ± 76, respectively; effect size = −4.28 [95% CI, −5.57 to −2.51], p < 0.001; severely osteoporotic: 21 ± 8 versus 35 ± 16, respectively; effect size = −1.13 [95% CI, −2.0 to 0.12], p = 0.027).

Conclusions

HFIA effectively augmented severely osteoporotic bone for screw purchase, but this effect was not seen for osteoporotic bone. In a model simulating both osteoporotic and severely osteoporotic bone, we found that HFIA can be used to repair stripped screw holes, but the resulting construct remains weaker than nonstripped controls.

Clinical Relevance

The HFIA material looks promising as a potential solution to stripped screws in osteoporotic bone. However, this material has yet to be tested in human bone. Furthermore, the fine mesh material could be damaged by autoclaving and could break off in vivo causing unknown tissue reactions. We recommend additional testing in a living animal model to better understand how living bone will react to the HFIA material.     

What Factors Predict Improvements in Outcomes Scores and Reoperations After the Bernese Periacetabular Osteotomy?

Background

The Bernese periacetabular osteotomy (PAO) has entered its fourth decade and is frequently used for corrective osteotomy in patients with acetabular dysplasia. Although our capacity to preserve the joint after corrective osteotomy is excellent, gaining a better understanding on how well patients function after this surgery is important as well.

Questions/purposes

(1) What changes in patient-reported outcomes scores occur in patients treated with PAO for hip dysplasia in the setting of a single-surgeon practice? (2) What are the predictors of clinical function and survivorship?

Methods

All 67 patients presenting to a single surgeon’s clinic with hip dysplasia treated with PAO between October 2005 and January 2013 were prospectively followed. Baseline demographic data as well as pre- and postoperative radiographic and functional measurements were obtained with a minimum of 1-year followup. Radiographic criteria included Tönnis grade, Tönnis angle, minimum joint space width, center-edge angle, presence of crossover sign, medial translation of the hip center, and alpha angle. We also used validated outcome measures including the WOMAC, the UCLA Activity Scale, and the SF-12. Multiple regression analysis was used to determine predictors of functional outcome scores.

Results

There were increases in WOMAC, UCLA, and SF-12 Physical scores. Higher preoperative alpha angle was associated with a lower postoperative WOMAC score (β = −0.47; 95% confidence interval [CI], −0.92 to −0.02; R² = 0.08; p = 0.04). The 5-year Kaplan-Meier survivorship was 94.1% (95% CI, 90.7–97.5) with reoperation (ie, hip arthroscopy and/or total hip arthroplasty) used as the endpoint for failure. With the limited numbers available, we could not identify any demographic or radiographic factors associated with reoperation.

Conclusions

Overall survivorship for the PAO at our center at 5 years is comparable to other clinical series with overall functional scores improving. A greater alpha angle preoperatively was associated with poorer patient-reported outcome scores. Further research is needed to determine how and when intraarticular cartilage damage associated with dysplasia needs to be addressed.

Level of Evidence

Level IV, therapeutic study.     

Are patients willing to pay for total shoulder arthroplasty? Evidence from a discrete choice experiment

Background

Total shoulder arthroplasty (TSA) is a common treatment to decrease pain and improve shoulder function in patients with severe osteoarthritis (OA). In Canada, patients requiring this procedure often wait a year or more. Our objective was to determine patient preferences related to accessing TSA, specifically comparing out-of-pocket payments for treatment, travel time to hospital, the surgeon’s level of experience and wait times.

Methods

We administered a discrete choice experiment among patients with end-stage shoulder OA currently waiting for TSA. Respondents were presented with 14 different choice sets, each with 3 options, and they were asked to choose their preferred scenario. A conditional logit regression model was used to estimate the relative preference and willingness to pay for each attribute.

Results

Sixty-two respondents completed the questionnaire. Three of the 4 attributes significantly influenced treatment preferences. Respondents had a strong preference for an experienced surgeon (mean 0.89 ± standard error [SE] 0.11), while reductions in travel time (−0.07 ± 0.04) or wait time (−0.04 ± 0.01) were of less importance. Respondents were found to be strongly averse (−1.44 ± 0.18) to surgical treatment by a less experienced surgeon and to paying out-of-pocket for their surgical treatment (−0.56 ± 0.05).

Conclusion

Our results suggest that patients waiting for TSA to treat severe shoulder OA have minimal willingness to pay for a reduction in wait time or travel time for surgery, yet will pay higher amounts for treatment by an experienced surgeon.     

A systematic review and meta-analysis of biological treatments targeting tumour necrosis factor α for sciatica

Purpose

Systematic review comparing biological agents, targeting tumour necrosis factor α, for sciatica with placebo and alternative interventions.

Methods

We searched 21 electronic databases and bibliographies of included studies. We included randomised controlled trials (RCTs), non-RCTs and controlled observational studies of adults who had sciatica treated by biological agents compared with placebo or alternative interventions.

Results

We pooled the results of six studies (five RCTs and one non-RCT) in meta-analyses. Compared with placebo biological agents had: better global effects in the short-term odds ratio (OR) 2.0 (95 % CI 0.7–6.0), medium-term OR 2.7 (95 % CI 1.0–7.1) and long-term OR 2.3 [95 % CI 0.5 to 9.7); improved leg pain intensity in the short-term weighted mean difference (WMD) −13.6 (95 % CI −26.8 to −0.4), medium-term WMD −7.0 (95 % CI −15.4 to 1.5), but not long-term WMD 0.2 (95 % CI −20.3 to 20.8); improved Oswestry Disability Index (ODI) in the short-term WMD −5.2 (95 % CI −14.1 to 3.7), medium-term WMD −8.2 (95 % CI −14.4 to −2.0), and long-term WMD −5.0 (95 % CI −11.8 to 1.8). There was heterogeneity in the leg pain intensity and ODI results and improvements were no longer statistically significant when studies were restricted to RCTs. There was a reduction in the need for discectomy, which was not statistically significant, and no difference in the number of adverse effects.

Conclusions

There was insufficient evidence to recommend these agents when treating sciatica, but sufficient evidence to suggest that larger RCTs are needed.

Electronic supplementary material

The online version of this article (doi:10.1007/s00586-013-2739-z) contains supplementary material, which is available to authorized users.     

How Are Dysplastic Hips Different? A Three-dimensional CT Study

Background

Surgical correction of acetabular dysplasia can postpone or prevent joint degeneration. The specific abnormalities that make up the dysplastic hip are controversial.

Questions/purposes

(1) What are the relative size, shape, and orientations of the typical nondysplastic hip? (2) How do these variables differ in the developmentally dysplastic hip? (3) Are there version differences between the acetabuli of dysplastic and nondysplastic hips? (4) Are there pairs of variables in which the change in one is always accompanied by a change in the other for both nondysplastic and dysplastic acetabuli?

Methods

Of 117 consecutive three-dimensional (3-D) CT scans performed for hip dysplasia between March 1988 and October 1995, 48 met criteria of developmentally dysplastic hips by plain radiography. These were retrospectively compared with 55 pelvic 3-D CT scans culled from 81 consecutive scans performed for reasons other than hip dysplasia (ie, hip pain, trauma, infection) that did not affect the hip or pelvic landmarks. The 3-D reconstructions were orientated anatomically for standardization of the measurements to be compared. Representative 3-D volumes of the acetabular space were constructed from which we could measure anatomic positions and dimensional information. One author performed all image orientation and measurements.

Results

Nondysplastic acetabuli are essentially hemispheric with height equal to width and twice the depth. The dysplastic acetabuli were elongated in females (52.4 ± 6.2 mm for dysplastic versus 46.5 ± 4.6 mm for nondysplastic (mean difference, 5.0; 95% confidence interval [CI], 1.9–8.0; p = 0.002) and shallower in both females (18.7 ± 4.9 mm for dysplastic versus 23.6 ± 4.0 mm for nondysplastic; mean difference, 6.5; 95% CI, 4.4–8.5; p < 0.0001) and males (21.1 ± 4.8 mm for dysplastic versus 25.0 ± 4.3 mm for nondysplastic, mean difference, 5.3; 95% CI, 2.6–8.1; p = 0.0002); width was similar to that of nondysplastic hips. Acetabular openings were slightly more vertical than nondysplastic hips in females (5°; 95% CI, 1.9–8.1; p = 0.002) but not in male subjects. The dysplastic acetabuli were smaller in volume (18% in females, p = 0.002, and 19% in males, p = 0.0012) and had less space occupied by the femoral head compared with nondysplastic hips (p < 0.0001 for females, p < 0.0001 for males). Dysplastic hip midacetabulum was 4° more anteverted in females (95% CI, 0.5–6.8; p = 0.022) but not for males (p = 0.538). The upper dysplastic acetabulum was more retroverted in females and males (10.2°; 95% CI, 5.5–15; p < 0.0001, and 7.0°; 95% CI, 0.6–13.4; p = 0.032, respectively). Acetabular volumes in nondysplastic and dysplastic hips were related to acetabular width but not to length.

Conclusions

Developmentally dysplastic acetabuli are not deficient in merely a single dimension but are globally deficient. The subluxated femoral head lies in the elongated and retroverted superior acetabulum, which becomes progressively shallower as the acetabulum increases in length. Focally deficient anterior or posterior femoral head coverage is uncommon. Current procedures that redirect the acetabulum, no matter how technically successful, cannot fully compensate for the incongruence of a spherical femoral head within a shallow and elongated acetabulum unless corrected at an early age when acetabular remodeling is possible. Early detection and treatment of acetabular dysplasia should be emphasized.

Level of Evidence

Level III, prognostic study.     

Lateralized Reverse Shoulder Arthroplasty Maintains Rotational Function of the Remaining Rotator Cuff

Background

Humeral rotation often remains compromised after nonlateralized reverse shoulder arthroplasty (RSA). Reduced rotational moment arms and muscle slackening have been identified as possible reasons for this impairment. Although several clinical studies suggest lateralized RSA may increase rotation, it is unclear whether this is attributable to preservation of rotational moment arms and muscle pretension of the remaining rotator cuff.

Questions/purposes

The lateralized RSA was analyzed to determine whether (1) the rotational moment arms and (2) the origin-to-insertion distances of the teres minor and subscapularis can be preserved, and (3) their flexion and abduction moment arms are decreased.

Methods

Lateralized RSA using an 8-mm resin block under the glenosphere was performed on seven cadaveric shoulder specimens. Preimplantation and postimplantation CT scans were obtained to create three-dimensional shoulder surface models. Using these models, function-specific moment arms and origin-to-insertion distances of three segments of the subscapularis and teres minor muscles were calculated.

Results

The rotational moment arms remained unchanged for the middle and caudal subscapularis and teres minor segments in all tested positions (subscapularis, −16.1 mm versus −15.8 mm; teres minor, 15.9 mm versus 15.3 mm). The origin-to-insertion distances increased or remained unchanged in any muscle segment apart from the distal subscapularis segment at 0° abduction (139 mm versus 145 mm). The subscapularis and teres minor had increased flexion moment arms in abduction angles smaller than 60° (subscapularis, 2.7 mm versus 8.3 mm; teres minor, −6.6 mm versus 0.8 mm). Abduction moment arms decreased for all segments (subscapularis, 4 mm versus −11 mm; teres minor, −3.6 mm versus −19 mm).

Conclusions

After lateralized RSA, the subscapularis and teres minor maintained their length and rotational moment arms, their flexion forces were increased, and abduction capability decreased.

Clinical Relevance

Our findings could explain clinically improved rotation in lateralized RSA in comparison to nonlateralized RSA.

Electronic supplementary material

The online version of this article (doi:10.1007/s11999-012-2692-x) contains supplementary material, which is available to authorized users.     

Does Rotator Cuff Repair Improve Psychologic Status and Quality of Life in Patients With Rotator Cuff Tear?

Background

Recently, psychological status, patient-centered outcomes, and health-related quality of life (HRQoL) in patients with scheduled or who underwent orthopaedic surgeries have been emphasized. The relationship between preoperative psychological status and postoperative clinical outcome in patients with rotator cuff repair has not yet been investigated.

Questions/purposes

The primary objective of this study was to investigate changes in psychological status (depression, anxiety, insomnia) and HRQoL after rotator cuff repair. The secondary objective was to assess whether preoperative depression, anxiety, and insomnia predict clinical outcome after rotator cuff repair.

Methods

Forty-seven patients who underwent rotator cuff repair prospectively completed the visual analog scale (VAS) pain score, the UCLA Scale, the American Shoulder and Elbow Surgeons’ Scale (ASES), the Hospital Anxiety and Depression Scale (HADS), the Pittsburgh Sleep Quality Index (PSQI), and the World Health Organization Quality-of-life Scale Abbreviated Version (WHOQOL-BREF) before surgery and at 3, 6, and 12 months after surgery. Repeated-measures analysis of variance was used to evaluate the serial changes in psychological parameters and outcome measurements. The chi-square test was also used to compare preoperative and postoperative prevalence of depression, anxiety, and insomnia. Finally, multiple regression analysis was applied to determine the relationship between preoperative psychological status and postoperative clinical outcome.

Results

With surgery, depression, anxiety, and insomnia decreased, whereas quality of life increased. The mean HADS-D and HADS-A scores and the mean PSQI score decreased from 3.7 ± 3.3, 4.3 ± 4.3, and 6.6 ± 3.6, respectively, before surgery to 2.1 ± 2.3, 1.4 ± 2.4, and 4.2 ± 3.3, respectively, at 12 months after surgery (HADS-D mean difference 1.6 [95% confidence interval {CI}, 0.6–2.6], p = 0.003; HADS-A mean difference 2.9 [1.5–4.4], p < 0.001; PSQI mean difference 2.4 [1.3–3.4], p < 0.001). The mean WHOQOL-BREF score increased from 60.4 ± 11.0 before surgery to 67.4 ± 11.8 at 12 months after surgery (mean difference −7.0 [95% CI, −10.7 to −3.4], p < 0.001). At 12 months after surgery, there were decreases in the prevalence of depression (six of 47 [22.8%] versus three of 47 [6.4%], p = 0.002), anxiety (11 of 47 [23.4%] versus two of 47 [4.3%], p = 0.016), and insomnia (33 of 47 [70.2%] versus 20 of 47 [42.6%], p = 0.022). Preoperative HADS-depression, HADS-anxiety, and PSQI scores did not correlate with the VAS pain score, UCLA, or ASES scores at 12 months after surgery.

Conclusions

Psychological status and HRQoL improved with decreasing pain and increasing functional ability from 3 months after surgery. Preoperative depression, anxiety, and insomnia did not predict poor outcome after rotator cuff repair. Our findings suggest that successful rotator cuff repair may improve psychological status and HRQoL.

Level of Evidence

Level II, prospective study.