The prognostic value of the head-shaft angle on hip displacement in children with cerebral palsy

BackgroundHip displacement is the second most common deformity in cerebral palsy (CP). The risk for hip displacement is related to the Gross Motor Function Classification System (GMFCS). Recently, the head-shaft angle (HSA) has been identified as a predictor for hip displacement and the aim of this study is to assess the predictive value of the HSA for hip displacement in CP.MethodsIn this retrospective cohort, we performed radiological measurements in 50 children on both hips. In children with GMFCS level II (30 hips), III (30 hips), IV (20 hips) and V (20 hips), we measured the HSA and migration percentage (MP) in three age intervals: age two years (T1), age four years (T2) and age seven years (T3).ResultsAt T1, the HSA was larger (more valgus) in hips that will displace than in hips that will not displace (174° vs. 166°; p = 0.001) and was also larger in higher GMFCS levels (IV–V vs. II–III) (172° vs. 165°; p < 0.001). At T1, GMFCS [odds ratio (OR) 14.7; p = 0.001] and HSA (OR 1.102; p = 0.043) were predictors for hip displacement at T3, but at T2, MP (OR 1.071; p = 0.010) was the only predictor for hip displacement at T3.ConclusionsThe HSA at two years is larger in hips that will displace and larger in children with higher GMFCS levels (IV–V). At age two years, GMFCS and HSA are valuable predictors for hip displacement, but at the age of four years, only MP should be used in the prediction of hip displacement.

Level of evidence

Prognostic study, level II.     

Effect of reverse shoulder design philosophy on muscle moment arms

This study analyzes the muscle moment arms of three different reverse shoulder design philosophies using a previously published method. Digital bone models of the shoulder were imported into a 3D modeling software and markers placed for the origin and insertion of relevant muscles. The anatomic model was used as a baseline for moment arm calculations. Subsequently, three different reverse shoulder designs were virtually implanted and moment arms were analyzed in abduction and external rotation. The results indicate that the lateral offset between the joint center and the axis of the humerus specific to one reverse shoulder design increased the external rotation moment arms of the posterior deltoid relative to the other reverse shoulder designs. The other muscles analyzed demonstrated differences in the moment arms, but none of the differences reached statistical significance. This study demonstrated how the combination of variables making up different reverse shoulder designs can affect the moment arms of the muscles in different and statistically significant ways. The role of humeral offset in reverse shoulder design has not been previously reported and could have an impact on external rotation and stability achieved post‐operatively. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:605–613, 2015.     

Generation and characterization of a novel shoulder contracture mouse model

Frozen shoulder is a relatively common disorder that leads to severe pain and stiffness in the shoulder joint. Although this disorder is self‐limiting in nature, the symptoms often persist for years, resulting in severe disability. Recent studies using human specimens and animal models have shown distinct changes in the gene expression patterns in frozen shoulder tissue, indicating that novel therapeutic intervention could be achieved by controlling the genes that are potentially involved in the development of frozen shoulder. To achieve this goal, it is imperative to develop a reliable animal joint contracture model in which gene expression can be manipulated by gene targeting and transgenic technologies. Here, we describe a novel shoulder contracture mouse model. We found that this model mimics the clinical presentation of human frozen shoulder and recapitulates the changes in the gene expression pattern and the histology of frozen shoulder and joint contracture in humans and other larger animal models. The model is highly reproducible, without any major complications. Therefore, the present model may serve as a useful tool for investigating frozen shoulder etiology and for identifying its potential target genes. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1732–1738, 2015.     

Posterior shoulder instability following anatomic total shoulder arthroplasty: A case report and review of management

We report a case of posterior shoulder instability following anatomic total shoulder arthroplasty (TSA). In addition, we present guidelines to aid in the management of posterior instability after TSA. A 50-year-old male underwent anatomic TSA for glenohumeral osteoarthritis. Postoperatively, the patient developed posterior instability secondary to glenoid retroversion. He did not improve despite conservative treatment. He underwent an arthroscopic posterior bone block procedure, 4-month after his index arthroplasty. At 14-month follow-up, the patient had regained near full motion and strength, and radiographs demonstrated osseous integration with no evidence of component loosening. Posterior instability following TSA is a relatively rare complication and challenging to manage. The posterior, arthroscopic iliac crest bone block grafting procedure represents a treatment option for posterior instability in the setting of a stable glenoid prosthesis following TSA.     

Arthroscopic repair of type II SLAP lesions: Clinical and anatomic follow-up

Aims:The aim was to evaluate the clinical and anatomic outcome of arthroscopic repair of type II SLAP lesions.Results:At a mean follow-up of 54-month, the mean American Shoulder and Elbow Surgeons Shoulder Index (ASES) scores improved from 52.1 preoperatively to 86.1 postoperatively (P < 0.0001) and the Simple Shoulder Test (SST) scores from 7.7 to 10.6 (P < 0.0002). Twenty-two out of the 25 patients (88%) stated that they would have surgery again. Of the 21 patients who had postoperative magnetic resonance imaging arthrographys (MRAs), 9 patients (43%) demonstrated dye tracking between the labrum bone interface suggestive of a recurrent tear and 12 patients (57%) had a completely intact repair. There was no significant difference in ASES, SST, and patient satisfaction scores in patients with recurrent or intact repairs.Conclusions:Arthroscopic repair of type II SLAP lesions demonstrated improvements in clinical outcomes. However, MRA imaging demonstrated 43% of patients with recurrent tears. MRA results do not necessarily correlate with clinical outcome.     

Triple labrum tears repaired with the JuggerKnot? soft anchor: Technique and results

Purpose:The 2-year outcomes of patients undergoing repair of triple labrum tears using an all-suture anchor device were assessed.Results:Overall total CS and FLEX-SF scores increased from 52.9 ± 20.4 to 84.3 ± 10.7 (P < 0.0001) and from 29.3 ± 4.7 to 42.0 ± 7.3 (P < 0.0001), respectively. When divided into two groups by whether or not glenohumeral arthrosis was present at the time of surgery (n = 9 each group), significant improvements in CS and FLEX-SF were obtained for both groups (P < 0.0015). There were no intraoperative complications. All patients, including contact athletes, returned to their preinjury level of sports activity and were satisfied. MRI evaluation revealed no instances of subchondral cyst formation or tunnel expansion. Anchor tracts appeared to heal with fibrous tissue, complete bony healing, or combined fibro-osseous healing.Conclusion:Our results are encouraging, demonstrating a consistent healing of the anchor tunnels through arthroscopic treatment of complex labrum lesions with a completely suture-based implant. It further demonstrates a meaningful improvement in patient outcomes, a predictable return to activity, and a high rate of patient satisfaction.

Level of Evidence:

Level IV case series.