Statistical Shape and Bone Property Models of Clinical Populations as the Foundation for Biomechanical Surgical Planning: Application to Shoulder Arthroplasty.

This work developed, validated, and compared statistical shape, statistical intensity, and statistical shape and intensity models (SSMs, SIMs, SSIMs) of scapulae from a clinical population. SSMs efficiently describe bone shape variation while SIMs describe bone material property variation, and SSIM's combine description of both variables. This work establishes these models' efficacy and whether they can be used in surgical planning. Models were developed using shoulder arthroplasty data of patients with bone erosion, which is challenging to treat and would benefit from improved surgical planning. Models were created using previously validated nonrigid registration and material property assignment processes that were optimized for scapula characteristics. The models were assessed using standard metrics, anatomical measurements, and correlation analyses. The SSM and SIM specificity and generalization error metrics were 3.4 mm and <1 mm and 184 HU and 156 HU, respectively. The SSIM did not achieve the same level of performance as the SSM and SIM in this study (e.g., shape generalization: SSIM-2.2 mm versus SSM-<1 mm). Anatomical correlation analysis showed that the SSM more effectively and efficiently described shape variation compared to the SSIM. The SSM and SIM modes of variation were not strongly correlated (e.g., rmax = 0.56 for modes explaining ≤2.1% of variance). The SSIM is outperformed by the SSM and SIM and the latter two are not strongly correlated; therefore, using the SSM and SIM in conjunction will generate synthetic bone models with realistic characteristics and thus can be used for biomechanical surgical planning applications.

Tensioning device increases coracoid bone block healing rates in arthroscopic Latarjet procedure with suture-button fixation.

BACKGROUND: There is growing interest in using suture buttons for coracoid fixation to avoid the complications associated with screws during the Latarjet procedure. However, achieving bone block healing is critical for successful shoulder stabilization and return to sport. The purpose of this study was to assess and compare the healing rates and positioning of the coracoid bone block fixed with cortical suture buttons that were either manually tensioned (using a knot pusher) or mechanically tensioned (using a tensioning device) during arthroscopic Latarjet procedures. METHODS: This prospective, nonrandomized, comparative study enrolled 69 consecutive patients (mean age, 27 years) who underwent an arthroscopic guided Latarjet procedure with suture-button fixation. Hand tensioning was performed in the first 34 shoulders, whereas the next 35 shoulders underwent mechanical tensioning. Twelve patients (17%) had a history of failed Bankart stabilization. The characteristics of the patients in each group in terms of age, sex, type of sport, bone loss, number of previous failed surgical procedures, smoking, and length of follow-up were comparable. Intraoperatively, the tensioning device was set at 100 N successively 3 times until complete immobilization of the bone block was confirmed, as assessed with a probe. The primary outcome measure was coracoid bone block union and position on computed tomography scan images at 6 months' follow-up. Secondary outcome measures included functional outcome scores, shoulder stability, return to sports, and complications at last follow-up. RESULTS: Overall, the rate of bone block healing was 74% (25 of 34 patients) in the hand-tensioning group and 94% (33 of 35 patients) in the mechanical tensioning group (P = .043). Smoking was an independent risk factor associated with nonunion (P < .001) in each group. Patient age, size of the preoperative glenoid bone defect (<20% or >20%), and a history of surgery were not found to have any influence. The tensioning modality did not affect the bone block position, which was subequatorial in 92% of the cases and flush with the glenoid rim in 92%. At a mean of 34 months of follow-up (range, 24-62 months), 96% of the patients (65 of 69) had a stable shoulder and 87% returned to sports. At final follow-up, no significant difference in clinical scores was noted between the groups; no neurologic or hardware complications were observed. CONCLUSION: Mechanical tensioning achieves significantly higher healing rates than hand tensioning during the arthroscopic Latarjet procedure with suture-button fixation. The use of a suture-tensioning device is a key step to the suture-button fixation technique during arthroscopic Latarjet procedures. By making the suture-button construct rigid, the tensioning device transforms the initially flexible suture into a "rigid fixation", similar to a bolt (or a rivet).

The Role of Arthroscopic Soft Tissue Reconstruction for Failed Bristow-Latarjet Procedure.

PURPOSE: To analyze the functional results after unipolar or bipolar arthroscopic soft tissue stabilization in the treatment of recurrent anterior instability after a coracoid bone block procedure. METHODS: We studied a retrospective series of 41 patients (33 male, 8 female) with recurrent anterior shoulder instability after Bristow (n = 7) or Latarjet (n = 34) coracoid bone block treated with unipolar (isolated Bankart, n = 22) or bipolar (Bankart + Hill-Sachs remplissage, n = 19) arthroscopic stabilization. RESULTS: The mean follow-up was 72 (25-208) months. Severe glenoid erosion (>25%) was found in 17 patients, and a medium or deep Hill-Sachs lesion (Calandra 2 and 3) was found in 24 patients. A radiographic control was available in 28 patients at final follow-up. Five patients (12%) presented a recurrence of instability (4 subluxations, 1 dislocation). Two patients required revision surgery, 1 in each group. At final follow-up, persistent anterior apprehension was more frequent in patients presenting with severe glenoid bone loss (P = .04) and in patients with medium or deep Hill-Sachs lesions who were treated with unipolar stabilization (P = .04). Return to sports was achieved in 81% of cases. Visual analog scale was 1.3 ± 2, subjective shoulder value was 83% ± 18%, Rowe score was 78 ± 24, and Walch-Duplay score was 76 ± 28. No patients developed severe glenohumeral arthritis (Samilson 4). CONCLUSIONS: Arthroscopic soft tissue stabilization provides good functional results after failed coracoid bone block with an acceptable rate of recurrence and a return to sports in most cases. Patients with significant Hill-Sachs lesions showed better results when treated with combined Bankart repair and Hill-Sachs remplissage. Severe glenoid bone loss was associated with poorer functional results. LEVEL OF EVIDENCE: Level IV, case series.

Arthroscopic Latarjet: Suture-Button Fixation Is a Safe and Reliable Alternative to Screw Fixation.

PURPOSE: To evaluate mid-term clinical outcomes, complications, bone-block healing, and positioning using suture-button fixation for an arthroscopic Latarjet procedure. METHODS: Patients with traumatic recurrent anterior instability and glenoid bone loss underwent guided arthroscopic Latarjet with suture-button fixation. We included patients with anterior shoulder instability, glenoid bone loss >20%, and radiographic and clinical follow-up minimum of 24 months. Patients with glenoid bone loss <20% or those that refused computed tomography imaging were excluded. Bone-block fixation was accomplished with 2 cortical buttons connected with a looped suture (4 strands). The looped suture was tied posteriorly with a sliding-locking knot. After transfer of the bone block on the anterior neck of the scapula, compression (100 N) was obtained with the help of a tensioning device. Clinical assessment was performed at 2 weeks, 3 months, 6 months, and then yearly with computed tomography completed at 2 weeks and 6 months to confirm bony union. RESULTS: A consecutive series of 136 patients underwent arthroscopic Latarjet with 121 patients (89%; mean age 27 years) available at final follow-up (mean follow-up, 26 months; range, 24-47 months). No neurologic complications or hardware failures were observed; no patients had secondary surgery for implant removal. The transferred coracoid process healed to the scapular neck in 95% of the cases (115/121). The bone block did not heal in 4 patients; it was fractured in 1 and lysed in another. Smoking was a risk factor associated with nonunion (P < .001). The coracoid graft was positioned flush to the glenoid face in 95% (115/121) and below the equator in 92.5% (112/121). At final follow-up, 93% had returned to sports, whereas 4 patients (3%) had a recurrence of shoulder instability. The subjective shoulder value for sports was 94 ± 3.7%. Mean Rowe and Walch-Duplay scores were 90 (range, 40-100) and 91 (range, 55-100), respectively. CONCLUSIONS: Suture-button fixation is an alternative to screw fixation for the Latarjet procedure, obtaining predictable healing with excellent graft positioning, and avoiding hardware-related complications. There was no need for hardware removal after suture-button fixation. The systematic identification of the axillary and musculocutaneous nerves reduced risk of neurologic injury. A low instability recurrence rate and excellent return to pre-injury activity level was found. Suture-button fixation is simple, safe, and may be used for both open and arthroscopic Latarjet procedure. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Comparison of the Ottawa Surgical Competency Operating Room Evaluation (O-SCORE) to a Single-Item Performance Score.

Construct: We compared a single-item performance score with the Ottawa Surgical Competency Operating Room Evaluation (O-SCORE) for their ability in assessing surgical competency. BACKGROUND: Surgical programs are adopting competency-based frameworks. The adoption of these frameworks for assessment requires tools that produce accurate and valid assessments of knowledge and technical performance. An assessment tool that is quick to complete could improve feasibility, reduce delays, and result in a higher volume of assessments of learners. Previous work demonstrated that the 9-item O-SCORE can produce valid results; the goal of this study was to determine if a single-item performance rating (Is candidate competent to independently complete procedure: yes or no) completed at a separate viewing would correlate to the O-SCORE, thus increasing feasibility of procedural competence assessment. APPROACH: Nineteen residents and 2 staff orthopedic surgeons from the University of Ottawa volunteered for a 2-part OSCE-style station including a written questionnaire and videotaped simulated open reduction and internal fixation midshaft radius fracture. Each performance was rated independently by 3 orthopedic surgeons using a single-item performance score (Time 1). The performances were assessed again 6 weeks later by the 3 raters using the O-SCORE (Time 2). Correlation between the single-item performance score and the O-SCORE were evaluated. RESULTS: Three orthopedic surgeons completed 21 ratings each resulting in 63 orthopedic ratings. There was a high level of correlation and agreement between the single-item performance score at Time 1 and Time 2 (κ correlation =0.72-1.00; p < .001; percentage agreement =90%-100%). The reliability of the O-SCORE at Time 2 with three raters was 0.83 and the internal consistency was 0.89. There was a tendency for each rater to assign more yes responses to the more senior trainees. CONCLUSIONS: A single-item performance score correlated highly with the O-SCORE in an orthopedic setting. A single-item score could be used to supplement a multi-item score with similar results in orthopedics. There is still benefit in completing multi-item scores such as the O-SCORE evaluations to guide specific areas of improvement and direct feedback.

All-arthroscopic, guided Eden-Hybbinette procedure using suture-button fixation for revision of failed Latarjet.

PURPOSE: To report the results of a guided arthroscopic Eden-Hybbinette procedure, using suture button for iliac crest bone graft fixation, in a series of patients with a prior failed Latarjet and persistent glenoid bone loss. METHODS: Seven consecutive patients (5 males, 2 females, mean age: 30.7 years [range, 17-47 years]) with recurrent anterior dislocations and glenoid deficiency greater than 20% underwent the all-arthroscopic revision procedure. The iliac crest bone graft and suture-button device (Bone-Link) were shuttled through the rotator interval. Specific drill guides were used and a suture tensioning device allowed bone graft compression. Previous broken screw shafts (3 patients) were left in situ. Graft placement and healing was assessed postoperatively with computed tomography imaging. RESULTS: No neurologic injury or hardware problems occurred, and no patient required further surgery. On computed tomography scan, optimal positioning (flush and under the equator) and healing of the bone graft was observed in all patients. At a mean follow-up of 21 months (range, 12-39 months), all but one patient were satisfied and had a stable shoulder; 5 returned to sports. The Constant score increased from 32 to 81 points, and the subjective shoulder value from 31% to 87% (P < .001). The Walch-Duplay and Rowe scores averaged 85.7 (range, 65-100) points and 86.4 (range, 70-100) points, respectively. CONCLUSION: Recurrence of anterior shoulder instability after a failed Latarjet procedure can be successfully treated by an all-arthroscopic Eden-Hybbinette procedure. Suture-button fixation is reliable and permits optimal positioning and predictable healing of the new bone graft; in addition, it is an appropriate fixation option in the setting of retained broken hardware.

Editorial Commentary: The Wake of the Dragon: Will the Orthopaedic Community Adopt the Shoulder Arthroscopic Latarjet Procedure as We Adopted the Arthroscopic Rotator Cuff Repair?

The Latarjet procedure is a complex and difficult operation when performed both with an open approach and arthroscopically. The difficulties come from the fact that it is a combined intra- and extra-articular procedure, and that working close to the brachial plexus may be frightening for surgeons. Because of the high complication and reoperation rates reported in the literature, this procedure is, at the moment, rejected by a large part of the orthopaedic community, specifically in North America. The Chinese experience shows, after the European one, that arthroscopic Latarjet is an efficient and irreplaceable option for the treatment of recurrent anterior shoulder instability in the context of capsular and/or glenoid deficiency. A recent study shows that the arthroscopic procedure provides accurate bone block positioning and high rates of healing, excellent clinical results (no recurrence of instability at 2-year follow-up), and low rates of complications (no neurovascular injury). Although the arthroscopic Latarjet should be approached with caution, the learning curve should not be thought of as prohibitive. To learn how to perform an arthroscopic Latarjet, surgeons should visit an experienced surgeon and take a course to practice on cadavers first. Although it will take time and effort to learn and perform this operation correctly, we should command our Chinese colleagues to encourage us to follow their path. There is no reason that in the near future the orthopaedic community does not adopt the arthroscopic Latarjet procedure, as we adopted the arthroscopic rotator cuff repair and other complex surgical procedures. Among the strongest reasons to perform the Latarjet procedure arthroscopically are the accuracy of graft placement, the safety for neurovascular structures provided by direct visualization and magnification, and the excellent clinical results allowing young people to go back to sport, including high-risk (contact, overhead) sports.

Imaging methods for quantifying glenoid and Hill-Sachs bone loss in traumatic instability of the shoulder: a scoping review.

BACKGROUND: Glenohumeral instability is a common problem following traumatic anterior shoulder dislocation. Two major risk factors of recurrent instability are glenoid and Hill-Sachs bone loss. Higher failure rates of arthroscopic Bankart repairs are associated with larger degrees of bone loss; therefore it is important to accurately and reliably quantify glenohumeral bone loss pre-operatively. This may be done with radiography, CT, or MRI; however no gold standard modality or method has been determined. A scoping review of the literature was performed to identify imaging methods for quantifying glenohumeral bone loss. METHODS: The scoping review was systematic in approach using a comprehensive search strategy and standardized study selection and evaluation. MEDLINE, EMBASE, Scopus, and Web of Science were searched. Initial selection included articles from January 2000 until July 2013, and was based on the review of titles and abstracts. Articles were carried forward if either reviewer thought that the study was appropriate. Final study selection was based on full text review based on pre-specified criteria. Consensus was reached for final article inclusion through discussion amongst the investigators. One reviewer extracted data while a second reviewer independently assessed data extraction for discrepancies. RESULTS: Forty-one studies evaluating glenoid and/or Hill-Sachs bone loss were included: 32 studies evaluated glenoid bone loss while 11 studies evaluated humeral head bone loss. Radiography was useful as a screening tool but not to quantify glenoid bone loss. CT was most accurate but necessitates radiation exposure. The Pico Method and Glenoid Index method were the most accurate and reliable methods for quantifying glenoid bone loss, particularly when using three-dimensional CT (3DCT). Radiography and CT have been used to quantify Hill-Sachs bone loss, but have not been studied as extensively as glenoid bone loss. CONCLUSIONS: Radiography can be used for screening patients for significant glenoid bone loss. CT imaging, using the Glenoid Index or Pico Method, has good evidence for accurate quantification of glenoid bone loss. There is limited evidence to guide imaging of Hill-Sachs bone loss. As a consensus has not been reached, further study will help to clarify the best imaging modality and method for quantifying glenohumeral bone loss.

Double incision repair technique with immediate mobilization for acute distal biceps tendon ruptures provides good results after 2 years in active patients.

INTRODUCTION: Surgical treatment of distal biceps tendon ruptures is recommended in an active population to avoid loss of strength, especially in supination and flexion. HYPOTHESIS: A double incision repair technique with immediate postoperative mobilization for acute distal biceps tendon ruptures is safe and provides good results after 2 years in active patients. MATERIAL AND METHODS: Seventy-four men (47±7 years) with acute tears of the distal biceps tendon tears were included in this retrospective single-center study. All patients were operated using the double-incision repair technique described by Morrey. The tendon was inserted with transosseous sutures into the biceps tuberosity. Patients were allowed to perform immediate postoperative active mobilization. A minimum follow-up of two years was required including clinical and radiological evaluation. RESULTS: Sixteen patients were lost to follow up leaving 58 (78%) patients for analysis with a mean follow-up of 53±19 months. At final follow-up, the mean evaluation for pain on the VAS scale was 0.22±0.7. Mean range of motion results included extension -1°±2°, flexion 138°±6°, pronation 72°±16° and supination 81°±10°. The strength ratio in flexion was 94±8% and in supination 90.5±12% compared to the contralateral limb. Subjective elbow value and DASH score were respectively 94±6% and 7.5±9%. All patients were satisfied or very satisfied and all except one returned to their previous sport. We noticed 2 heterotopic ossifications and one patient needed a reoperation for a radioulnar synostosis. Neither re-rupture nor nerve injury were observed. DISCUSSION: A double incision technique for distal biceps tendon repair is a minimally invasive procedure with reliable results. Morrey's modification of the initial procedure associated with early mobilization is associated with a low rate of complications and limited the occurrence of synostosis or ossifications. LEVEL OF EVIDENCE: IV, case series, with no comparison group.

Combined All-arthroscopic Hill-Sachs Remplissage, Latarjet, and Bankart Repair in Patients With Bipolar Glenohumeral Bone Loss.

Patients presenting with recurrent shoulder instability and bipolar glenohumeral bone loss are at risk of failed standard soft-tissue repair techniques. Even isolated bony-stabilization procedures such as the Latarjet or remplissage technique may not provide sufficient stability in the face of combined bone loss. We use a combined all-arthroscopic remplissage, Latarjet, and Bankart repair for patients with significant combined glenohumeral bone loss and/or in the revision setting. This allows reconstruction of both the Hill-Sachs and glenoid bone defects and repair of the capsulolabral complex in a minimally invasive manner. Furthermore, the use of cortical-button fixation of the coracoid bone graft may reduce the risk of hardware-related complications while still achieving excellent bone union.

Decreased hypertrophic differentiation accompanies enhanced matrix formation in co-cultures of outer meniscus cells with bone marrow mesenchymal stromal cells.

INTRODUCTION: The main objective of this study was to determine whether meniscus cells from the outer (MCO) and inner (MCI) regions of the meniscus interact similarly to or differently with mesenchymal stromal stem cells (MSCs). Previous study had shown that co-culture of meniscus cells with bone marrow-derived MSCs result in enhanced matrix formation relative to mono-cultures of meniscus cells and MSCs. However, the study did not examine if cells from the different regions of the meniscus interacted similarly to or differently with MSCs. METHODS: Human menisci were harvested from four patients undergoing total knee replacements. Tissue from the outer and inner regions represented pieces taken from one third and two thirds of the radial distance of the meniscus, respectively. Meniscus cells were released from the menisci after collagenase treatment. Bone marrow MSCs were obtained from the iliac crest of two patients after plastic adherence and in vitro culture until passage 2. Primary meniscus cells from the outer (MCO) or inner (MCI) regions of the meniscus were co-cultured with MSCs in three-dimensional (3D) pellet cultures at 1:3 ratio, respectively, for 3 weeks in the presence of serum-free chondrogenic medium containing TGF-ß1. Mono-cultures of MCO, MCI and MSCs served as experimental control groups. The tissue formed after 3 weeks was assessed biochemically, histochemically and by quantitative RT-PCR. RESULTS: Co-culture of inner (MCI) or outer (MCO) meniscus cells with MSCs resulted in neo-tissue with increased (up to 2.2-fold) proteoglycan (GAG) matrix content relative to tissues formed from mono-cultures of MSCs, MCI and MCO. Co-cultures of MCI or MCO with MSCs produced the same amount of matrix in the tissue formed. However, the expression level of aggrecan was highest in mono-cultures of MSCs but similar in the other four groups. The DNA content of the tissues from co-cultured cells was not statistically different from tissues formed from mono-cultures of MSCs, MCI and MCO. The expression of collagen I (COL1A2) mRNA increased in co-cultured cells relative to mono-cultures of MCO and MCI but not compared to MSC mono-cultures. Collagen II (COL2A1) mRNA expression increased significantly in co-cultures of both MCO and MCI with MSCs compared to their own controls (mono-cultures of MCO and MCI respectively) but only the co-cultures of MCO:MSCs were significantly increased compared to MSC control mono-cultures. Increased collagen II protein expression was visible by collagen II immuno-histochemistry. The mRNA expression level of Sox9 was similar in all pellet cultures. The expression of collagen × (COL10A1) mRNA was 2-fold higher in co-cultures of MCI:MSCs relative to co-cultures of MCO:MSCs. Additionally, other hypertrophic genes, MMP-13 and Indian Hedgehog (IHh), were highly expressed by 4-fold and 18-fold, respectively, in co-cultures of MCI:MSCs relative to co-cultures of MCO:MSCs. CONCLUSIONS: Co-culture of primary MCI or MCO with MSCs resulted in enhanced matrix formation. MCI and MCO increased matrix formation similarly after co-culture with MSCs. However, MCO was more potent than MCI in suppressing hypertrophic differentiation of MSCs. These findings suggest that meniscus cells from the outer-vascular regions of the meniscus can be supplemented with MSCs in order to engineer functional grafts to reconstruct inner-avascular meniscus.