A modified Delphi consensus statement on patellar instability: part I.

Aims: The aim of this study was to establish consensus statements on the diagnosis, nonoperative management, and indications, if any, for medial patellofemoral complex (MPFC) repair in patients with patellar instability, using the modified Delphi approach. Methods: A total of 60 surgeons from 11 countries were invited to develop consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest within patellar instability. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered to be unanimous. Results: Of 27 questions and statements on patellar instability, three achieved unanimous consensus, 14 achieved strong consensus, five achieved consensus, and five did not achieve consensus. Conclusion: The statements that reached unanimous consensus were that an assessment of physeal status is critical for paediatric patients with patellar instability. There was also unanimous consensus on early mobilization and resistance training following nonoperative management once there is no apprehension. The statements that did not achieve consensus were on the importance of immobilization of the knee, the use of orthobiologics in nonoperative management, the indications for MPFC repair, and whether a vastus medialis oblique advancement should be performed.

A modified Delphi consensus statement on patellar instability: part II.

Aims: The aim of this study was to establish consensus statements on medial patellofemoral ligament (MPFL) reconstruction, anteromedialization tibial tubercle osteotomy, trochleoplasty, and rehabilitation and return to sporting activity in patients with patellar instability, using the modified Delphi process. Methods: This was the second part of a study dealing with these aspects of management in these patients. As in part I, a total of 60 surgeons from 11 countries contributed to the development of consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered unanimous. Results: Of 41 questions and statements on patellar instability, none achieved unanimous consensus, 19 achieved strong consensus, 15 achieved consensus, and seven did not achieve consensus. Conclusion: Most statements reached some degree of consensus, without any achieving unanimous consensus. There was no consensus on the use of anchors in MPFL reconstruction, and the order of fixation of the graft (patella first versus femur first). There was also no consensus on the indications for trochleoplasty or its effect on the viability of the cartilage after elevation of the osteochondral flap. There was also no consensus on postoperative immobilization or weightbearing, or whether paediatric patients should avoid an early return to sport.

Meniscus Allograft Transplantation Augmented With Autologous Bone Marrow Aspirate Concentrate.

Meniscus allograft transplantation (MAT) has been shown to be a feasible surgical option for younger patients, below 50 years of age who have meniscal insufficiency and have failed conservative treatment measures. In this technical note, we describe a procedure of harvesting and injecting bone marrow aspirate concentrate in a meniscus allograft during a MAT procedure, which may allow for longer lasting transplants and improve patient outcomes. In this technical note, bone marrow aspirate concentrate is harvested arthroscopically from the intercondylar notch at the surgical site, which prevents additional donor site morbidity, as seen with harvesting from other locations, such as the iliac crest. This also reduces operating time, since harvesting from the iliac crest requires different patient positioning and usually additional anesthesia. The authors of this surgical technique believe that biological augmentation during MATs will assist surgeons in maximizing graft survivorship and, ultimately, lead to better patient outcomes.

Surgeon-Directed Arthroscopic Infiltration Between the Popliteal Artery and Capsule of the Knee (IPACK) Block: Technical Description.

Advances in regional anesthesia techniques for knee surgery have led to drastic improvements in postoperative pain control and have reduced reliance on perioperative opioid analgesics. The infiltration between the popliteal artery and capsule of the knee (IPACK) block has been a useful tool for providing posterior knee analgesia as an adjuvant to traditional femoral or adductor canal blocks in knee surgery. We present a simple and reproducible technique for the arthroscopic administration of this block.

Effectiveness of an Accelerated Rehabilitation Protocol After Tibial Tubercle Osteotomy.

Background: Patients with recurrent patellar dislocations with trochlear dysplasia are commonly treated surgically with a tibial tubercle osteotomy (TTO). Recovery and rehabilitation processes are often nonoperative out of concern for fixation failure or fracture. A more accelerated rehabilitation protocol allowing for early weightbearing and quadriceps strengthening may help to improve patient outcomes as long as complications are not increased. Purpose: To evaluate the safety and effectiveness of an accelerated weightbearing and early strengthening postoperative rehabilitation program for patients who undergo TTO. Study Design: Case series; Level of evidence, 4. Methods: Included were patients who underwent unilateral/staged bilateral TTO performed by a single surgeon between August 2013 and February 2018 with ≥6 months of follow-up. The surgical indication was primarily for patients with recurrent patellar instability. In all cases, a diagnostic arthroscopy was performed to evaluate the cartilage surfaces and document patellar tracking. The TTO was performed using a freehand technique and two 3.5-mm fully threaded screws for fixation. Patients underwent an accelerated postoperative rehabilitation program that allowed for weightbearing and lower extremity strengthening starting at 4 weeks. Objective and subjective outcome measures included any postoperative complications, knee range of motion, and patient-reported outcome scores (Kujala Anterior Knee Pain Scale [AKPS] and Knee injury and Osteoarthritis Outcome Score composite [(KOOS5]). Results: A total of 51 knees in 50 patients (38 female, 12 male) with a mean age of 31.24 ± 12.57 years were included in the final analysis. Compared with preoperative values, postoperative maximum knee flexion was significantly improved (117.67° ± 32.65° vs 131.12° ± 9.02°, respectively; P = .022). Postoperative complications included 6 patients with arthrofibrosis requiring manipulation under anesthesia, 4 with removal of symptomatic hardware, 1 tibial fracture (due to a fall), and 1 conversion to patellofemoral arthroplasty. The mean postoperative AKPS and KOOS5 scores were 72.98 ± 21.51 and 75.05 ± 16.02, respectively. Conclusion: Accelerated postoperative rehabilitation in TTO patients was an effective means of treatment with good subjective and objective outcomes and complication rates lower than traditional rehabilitation protocols.

Surgical Considerations in Revision Anterior Cruciate Ligament Reconstruction.

Revision anterior cruciate ligament reconstruction (rACLR) procedures are often technically and intellectually challenging. However, with careful preoperative evaluation and planning, the likelihood of success can be maximized. Understanding the various etiologies of and contributors to primary ACLR failure can guide the surgical plan in terms of whether concomitant procedures are needed. Although successful outcomes have been reported with both one-stage and two-stage rACLRs, appropriate patient selection is important. Overall, clinical outcomes including patient-reported outcomes, graft failure rates, and return to sport are worse after rACLR compared with primary ACLR. It is important to review the preoperative evaluation, surgical considerations, and outcomes of rACLR.

High Rate of Initially Overlooked Kaplan Fiber Complex Injuries in Patients With Isolated Anterior Cruciate Ligament Injury.

BACKGROUND: Injuries to the Kaplan fiber complex (KFC) are not routinely assessed for in the anterior cruciate ligament (ACL)-deficient knee during preoperative magnetic resonance imaging (MRI). As injuries to the KFC lead to anterolateral rotatory instability (ALRI) in the ACL-deficient knee, preoperative detection of these injuries on MRI scans may help surgeons to individualize treatment and improve outcomes, as well as to reduce failure rates. PURPOSE: To retrospectively determine the rate of initially overlooked KFC injuries on routine MRI in knees with isolated primary ACL deficiency. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients who underwent isolated ACL reconstruction between August 2013 and December 2019 were identified. No patient had had Kaplan fiber (KF) injury identified on the initial reading of the MRI scan or at the time of surgery. Preoperative knee MRI scans (minimum 1.5 T) were reviewed and injuries to the proximal and distal KFs were recorded by 3 independent reviewers. KF length and distance to nearby anatomic landmarks (the lateral joint line and the lateral femoral epicondyle) were measured. Additional radiological findings, including bleeding, lateral femoral notch sign, and bone marrow edema (BME), were identified to detect correlations with KFC injury. RESULTS: The intact KFC could reliably be identified by all 3 reviewers (85.9% agreement; Kappa, 0.716). Also, 53% to 56% of the patients with initially diagnosed isolated ACL ruptures showed initially overlooked injuries to the KFC. Injuries to the distal KFs were more frequent (48.1%, 53.8%, and 43.3% by the first, second, and third reviewers, respectively) than injuries to the proximal KFs (35.6%, 47.1%, and 45.2% by the first, second, and third reviewers, respectively). Bleeding in the lateral supracondylar region was associated with KFC injuries (P = .023). Additionally, there was a positive correlation between distal KF injuries and lateral tibial plateau BME (P = .035), but no associations were found with the lateral femoral notch sign or other patterns of BME, including pivot-shift BME. CONCLUSION: KF integrity and injury can be reliably detected on routine knee MRI scans. Also, 53% to 56% of the patients presenting with initially diagnosed isolated ACL ruptures had concomitant injuries to the KFC. This is of clinical relevance, as ACL injuries diagnosed by current routine MRI examination protocols may come with a high number of occult or hidden KFC injuries. As injuries to the KFC contribute to persistent ALRI, which may influence ACL graft failure or reoperation rates, significant improvements in preoperative diagnostic imaging are required to determine the exact injury pattern and to assist in surgical decision making.

A new approach to superior capsular reconstruction with hamstring allograft for irreparable posterosuperior rotator cuff tears: a dynamic biomechanical evaluation.

BACKGROUND: Superior capsular reconstruction (SCR) treatment of massive, symptomatic, irreparable rotator cuff tears (RCTs) has become a more recently used procedure. However, there is a lack of consensus surrounding optimal graft choice for the SCR technique, and current dermal grafts have increased cost and are technically challenging because of a need for multiple implants. The purpose of this study was to biomechanically investigate a biological lower-cost alternative as a support for the superior capsule reconstruction concept: an isolated semitendinosus tendon (STT) allograft and a combination graft with the long head of the biceps tendon (LHBT) in an established massive posterosuperior RCT cadaver model. METHODS: Ten fresh-frozen cadaveric shoulders (53.3 ± 12.4 years: range: 26-65) were tested on an established dynamic shoulder simulator using dynamic muscle loading. Cumulative deltoid forces, maximum abduction angle, and superior humeral head translation were compared across 4 testing conditions: (1) intact state, (2) massively retracted (Patte III), irreparable posterosuperior RCT, (3) SCR repair using an STT allograft, and (4) SCR repair using a combined STT-LHBT repair. RESULTS: Intact shoulders required a mean deltoid force of 154.2 ± 20.41 N to achieve maximum glenohumeral abduction (55.3° ± 2.3°). Compared with native shoulders, the maximum abduction angle decreased following a massively retracted posterosuperior RCT by 52% (28.3° ± 8.4°; P < .001), whereas the cumulative deltoid forces increased by 48% (205.3 ± 40.9 N; P = .001). The STT repair and the STT-LHBT repair improved shoulder function compared with the tear state, with a mean maximum abduction angle of 30.6° ± 9.0° and 31.8° ± 7.7° and a mean deltoid force of 205.3 ± 40.9 N and 201.0 ± 34.0 N, respectively, but this was not statistically significant (P > .05). The STT-LHBT repair significantly improved the range of motion with respect to the tear state (P = .04). CONCLUSIONS: In a dynamic shoulder simulator model, both the STT and the STT-LHBT repair techniques improved glenohumeral joint kinematics in an amount similar to previously reported "traditional" SCR techniques for treatment of an irreparable posterosuperior RCT.

Use of a Superolateral Portal and 70° Arthroscope to Optimize Visualization of Patellofemoral Tracking and Osteochondral Lesions in Patients With Recurrent Patellar Instability.

Surgical treatment of patellofemoral instability and associated cartilaginous lesions can be technically challenging. Visualization of patellar tracking and underlying osteochondral lesions is paramount to operative success. To treat these conditions effectively, a comprehensive arthroscopic assessment of the patellofemoral joint as well as dynamic visualization of patella tracking must be achieved. Visualization of the patellofemoral joint-in particular, the articular cartilage of the patella and trochlea morphology-can be difficult when using traditional anteromedial or anterolateral portals and a 30° arthroscope lens. The technique described here uses an accessory superolateral portal and a 70° arthroscope to achieve significantly improved visualization of the patellofemoral articulation, in particular the chondral surfaces. This vantage point aids the surgeon in effectively evaluating patellar tracking, trochlea morphology, and importantly, osteochondral lesion location to help guide treatment algorithms in the patellofemoral joint.

Epidemiology of Shoulder Instability Injuries in Collision Collegiate Sports From 2009 to 2014.

PURPOSE: To describe the types, mechanisms, and severity of shoulder instability injuries in collegiate collision athletes during the 2009-2010 through 2013-2014 academic years using the National Collegiate Athletic Association Injury Surveillance Program; to compare the injury incidence between men's collision sports and their women's non-collision counterparts, when possible; and to compare injury outcomes between Divisions I, II, and III. METHODS: Data regarding men's football, wrestling, ice hockey, and lacrosse, as well as women's ice hockey and lacrosse, were obtained. Injuries requiring attention from a health care provider were reported. Incidence rates per 100,000 athlete-exposures (AEs) were calculated with 95% confidence intervals (CIs). Analysis of variance was used to compare time loss (TL), and χ2 analysis was used to compare surgery rates between divisions. RESULTS: A total of 445 shoulder instability injuries occurred in 1,421,561 AEs from 2009-2010 to 2013-2014 (incidence rate, 31.30 injuries/100,000 AEs; 95% CI, 28.4-34.21 injuries/100,000 AEs). Subluxation accounted for 59.1% of injuries, with anterior subluxation (35.3%) being the most common injury. Dislocation resulted in the most TL per injury (17.58 days). Mean TL for all injuries was 8.17 days (standard deviation, 7.21 days). When non-time-loss injuries were excluded from analysis, players experienced a mean TL of 18.34 days (standard deviation, 8.44 days). Divisions I (4.77 days), II (20.52 days), and III (11.23 days) differed significantly in mean TL (P = .01). Of the injuries, 29.3% required surgery. The surgery rates for Divisions I (32.9%), II (38.1%), and III (19.4%) also differed significantly (P = .04). Men's ice hockey and lacrosse players sustained a 2.17-fold (95% CI, 1.04-4.50) higher incidence of shoulder instability than their female counterparts. CONCLUSIONS: Anterior subluxation and dislocation accounted for 52.1% of all shoulder instability injuries. Injured athletes missed 8 days on average, and nearly 30% of injuries required surgery. Surgery rates and TL were significantly different between Divisions I, II, and III. Female athletes playing non-collision ice hockey and lacrosse experienced significantly lower shoulder instability rates than their male counterparts. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Patellofemoral Contact Pressures After Patellar Distalization: A Biomechanical Study.

PURPOSE: To measure the patellofemoral contact pressure in early flexion after a tibial tubercle distalization osteotomy. METHODS: Ten matched-pair fresh-frozen cadaveric knees were studied. The average Blackburne-Peel ratio of the native knees was 0.91. The knees were placed on a testing rig, with a fixed femur and tibia mobile through 90° of flexion. Individual quadriceps heads and the iliotibial band were separated and loaded with 205 N in anatomic directions using a weighted pulley system. A straight tubercle distalization osteotomy of 1 cm was performed and fixed with screws, with and without a lateral release. Patellofemoral contact pressures were measured at 0°, 10°, 20°, 30°, 45°, 60°, and 90° of flexion using pressure-sensitive films on the medial trochlea and lateral trochlea. Contact force, area, and pressure were measured in the following states: (1) in the native knee, (2) after distalization, and (3) after distalization with lateral release. RESULTS: The average Blackburne-Peel ratio after distalization was 0.64. Tibial tubercle distalization resulted in a 6-fold increase in mean contact pressure at 0° (0.15 MPa vs 0.90 MPa, P < .001) and a 55% increase at 10° of flexion (0.70 MPa vs 1.09 MPa, P = .02). Mean contact pressure was similar from 20° to 90° of flexion (P > .1). After distalization, the total contact area was significantly higher at 0° of flexion (17.7 mm2 vs 58.4 mm2, P = .02). Lateral release after distalization did not significantly change contact pressure (P > .21). CONCLUSIONS: Our results suggest that patella baja, as a result of excessive patellar distalization, can cause increased patellofemoral contact pressures during early flexion at 0° and 10°. No changes were seen in contact pressure from 20° to 90°. CLINICAL RELEVANCE: Care should be taken to prevent excessive distalization of the patella to avoid patella baja and increased patellofemoral contact pressures during early flexion.

Pectoralis Major Repair: A Biomechanical Analysis of Modern Repair Configurations Versus Traditional Repair Configuration.

BACKGROUND: Pectoralis major (PM) ruptures are increasingly common, and a variety of surgical techniques have been described. However, tested techniques have demonstrated diminished strength with inadequate restoration of the footprint and suture failure at relatively low loads. Purpose/Hypothesis: The purpose was to biomechanically compare PM transosseous suture repair (current gold standard) to modern PM repair techniques that use larger caliber sutures, suture tape, and unicortical button fixation (UBF). The null hypothesis was that there would be no mechanical difference between repair techniques and no difference in the amount of footprint restoration. STUDY DESIGN: Controlled laboratory study. METHODS: Twenty-four fresh-frozen cadaveric shoulders controlled for age and bone mineral density were randomized equally to 4 groups: (1) UBF, suture tape; (2) UBF, No. 5 suture, suture tape; (3) bone trough with No. 2 suture; and (4) native PM tendon group; all groups were tested to failure. The specimens were tested under cycling loads (10 N to 125 N) with a final load-to-failure test at 1 mm/s. Failure modes were classified by location and cause of rupture based on optical markers, while tendon footprint length was measured to determine amount of footprint restoration. RESULTS: For fixation strength, the mean peak load was significantly greater in the native tendon (1816 ± 706 N) versus UBF/No. 5 suture/suture tape (794 ± 168 N), UBF/suture tape (502 ± 201 N), and bone trough (492 ± 151 N) ( P < .001 for all). UBF/No. 5 suture/suture tape featured the lowest displacement superiorly (1.09 ± 0.47 mm) and inferiorly (1.14 ± 0.39 mm) with a significant difference compared with bone trough. With regard to tendon footprint reapproximation, cortical button fixation best approximated native tendon footprint length versus bone trough. CONCLUSION: Based on peak failure load, the UBF/No. 5 suture/suture tape construct demonstrated 61% greater construct strength than a traditional bone trough technique. Moreover, displacement after cyclic loading was by far smallest in the UBF/No. 5 suture/suture tape construct. Therefore, repair constructs with larger caliber suture and suture tape provide a measurable improvement in construct strength versus traditional PM repair techniques in a biomechanical model and may be advantageous for repair. CLINICAL RELEVANCE: Cortical button fixation with larger caliber suture and suture tape allows for a significantly better PM repair than more traditional techniques at the time of surgery, which may ultimately result in improved clinical outcomes if implemented in surgical practice.

Calcium phosphate cement enhances the torsional strength and stiffness of high tibial osteotomies.

PURPOSE: There has been a resurgence in the use of opening wedge high tibial osteotomy (owHTO). Calcium phosphate cement has been shown to improve strength in compression for augmentation of tibial plateau and owHTO fixation. However, knee kinematics includes a torsional load during ambulation, which is as yet unstudied in this model. The purpose of this paper is to investigate the effect of injectable calcium phosphate cement on the biomechanical stability of standard high tibial osteotomy defect with applied torsional load and ultimate stiffness of the supporting construct. METHODS: Testing was performed on 22 bone mineral density-matched and age-matched cadaver specimens. Intact specimens were treated with 10° opening wedge osteotomies, identical surgical techniques as clinically used and fixation provided by iBalance© PEEK implant (Arthrex, Naples FL). Nine specimens were augmented with calcium phosphate injectable cement, Quickset (Arthrex Inc., Naples Fl). Constructs were for construct stiffness, torsional loads to failure, and mechanisms of failure. As a gold-standard comparison group, four samples were tested with a titanium, fixed angle device alone: Contourlock plate (Arthrex Inc., Naples Fl). RESULTS: Peak torque to failure was significantly greater in samples augmented with calcium phosphate bone cement (23.0 ± 9.6 Nm) compared with specimens fixed with PEEK implant alone (18.1 ± 7.3). Construct stiffness in torsion was also significantly improved with bone cement application (349.0 ± 126.8 Nm/°) compared with PEEK implant alone (202.2 ± 153.4 Nm/°) and fixed angle implant system (142.9 ± 74.7 Nm/°). CONCLUSION: Injectable calcium phosphate cement improves the initial maximal torsional strength and stiffness of high tibial osteotomy construct.

Sports-related wrist and hand injuries: a review.

BACKGROUND: Hand and wrist injuries are common during athletics and can have a significant impact especially if initially disregarded. Due to their high level of physical demand, athletes represent a unique subset of the population. MAIN BODY: The following is an overview of hand and wrist injuries commonly seen in athletics. Information regarding evaluation, diagnosis, conservative measures, and surgical treatment are provided. CONCLUSION: Knowledge of these entities and special consideration for the athlete can help the team physician effectively treat these players and help them achieve their goals.

Recurrent Anterior Shoulder Instability With Combined Bone Loss: Treatment and Results With the Modified Latarjet Procedure.

BACKGROUND: Recurrent anterior glenohumeral dislocation in the setting of an engaging Hill-Sachs lesion is high. The Latarjet procedure has been well described for restoring glenohumeral stability in patients with >25% glenoid bone loss. However, the treatment for patients with combined humeral head and mild (<25%) glenoid bone loss remains unclear. PURPOSE/HYPOTHESIS: This study reports on the outcomes of the modified Latarjet for patients with combined humeral and glenoid defects and compares the results for patients with ≤25% glenoid bone loss versus patients with >25% glenoid bone loss. The hypothesis was that the 2 groups would have equivalent subjective outcomes and recurrence rates. STUDY DESIGN: Cohort Study; Level of evidence, 3. METHODS: Modified Latarjet was performed in 40 patients with recurrent anterior shoulder instability, engaging Hill-Sachs by examination confirmed with arthroscopy, and ≤25% anterior glenoid bone loss (group A). A second group of 12 patients were identified to have >25% glenoid bone loss with an engaging Hill-Sachs lesion (group B). The mean follow-up time was 3.5 years. All patients were assessed for their risk of recurrence using the Instability Severity Index score and Beighton score and had preoperative 3-dimensional imaging to assess humeral and glenoid bone loss. Single Assessment Numeric Evaluation (SANE), Western Ontario Shoulder Instability Index (WOSI), recurrence rate, radiographs, range of motion, and dynamometer strength were used to assess outcomes. A multivariate analysis was performed. RESULTS: Glenoid bone loss averaged 15% in group A compared with 34% in group B. Both groups had comparable WOSI scores (356 vs 475; P = .311). In multivariate analysis, the number of previous surgeries and Beighton score were directly correlated with WOSI score in Latarjet patients. The SANE score was better in group A (86 vs 77; P = .02). Group B experienced more loss of external rotation (9.2° vs 15.8°; P = .0001) and weaker thumbs-down abduction and external rotation strength (P < .032). Subscapularis, abduction, and external rotation strength averaged at least 75% of the contralateral shoulder in both groups. Graft resorption was similar in both groups (32% vs 33%; P < .999). The overall recurrent instability rate for the study, defined as any subsequent subluxations or dislocation, was 15%; recurrent instability rates (15% vs 17%; P > .999) were similar for both groups. The complication rate was 25% for both groups. CONCLUSION: The modified Latarjet procedure provides satisfactory outcomes for patients with combined bone loss, which is known to have high recurrence rates with traditional arthroscopic stabilization. Previous surgical stabilization procedures and the Beighton score adversely affect outcome after modified Latarjet. Furthermore, the number of previous surgeries and Beighton score can be used to predict WOSI score in Latarjet patients. Further study is needed to determine if these results hold true in the long term.

Current concepts in the treatment of acromioclavicular joint dislocations.

PURPOSE: To conduct a systematic review of the literature in relation to 3 considerations in determining treatment options for patients with acromioclavicular (AC) joint dislocations: (1) operative versus nonoperative management, (2) early versus delayed surgical intervention, and (3) anatomic versus nonanatomic techniques. METHODS: The PubMed database was searched in October 2011 using the single term acromioclavicular and the following search limits: any date, humans, English, and all adult (19+). Studies were included if they compared operative with nonoperative treatment, early with delayed surgical intervention, or anatomic with nonanatomic surgical techniques. Exclusion criteria consisted of the following: Level V evidence, laboratory studies, radiographic studies, biomechanical studies, fractures or revisions, meta-analyses, and studies reporting preliminary results. RESULTS: This query resulted in 821 citations. Of these, 617 were excluded based on the title of the study. The abstracts and articles were reviewed, which resulted in the final group of 20 studies that consisted of 14 comparing operative with nonoperative treatment, 4 comparing early with delayed surgical intervention, and 2 comparing anatomic with nonanatomic surgical techniques. The lack of higher level evidence prompted review of previously excluded studies in an effort to explore patterns of publication related to operative treatment of the AC joint. This review identified 120 studies describing 162 techniques for operative reconstruction of the AC joint. CONCLUSIONS: There is a lack of evidence to support treatment options for patients with AC joint dislocations. Although there is a general consensus for nonoperative treatment of Rockwood type I and II lesions, initial nonsurgical treatment of type III lesions, and operative intervention for Rockwood type IV to VI lesions, further research is needed to determine if differences exist regarding early versus delayed surgical intervention and anatomic versus nonanatomic surgical techniques in the treatment of patients with AC joint dislocations. LEVEL OF EVIDENCE: Level III, systematic review of Level II and Level III studies and one case series.

Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.

UNLABELLED: Although allograft use for primary anterior cruciate ligament reconstruction has continued to increase during the last 10 years, concerns remain regarding the long-term function of allografts (primarily that they may stretch with time) and clinical efficacy compared with autograft tendons. We attempted to address these issues by prospectively comparing identical quadrupled hamstring autografts with allograft constructs for primary anterior cruciate ligament reconstruction in patients with a minimum followup of 3 years. Eighty-four patients (37 with autografts and 47 with allografts) were enrolled; the mean followup was 52 +/- 11 months for the autograft group and 48 +/- 8 months for the allograft group. Outcome measurements included objective and subjective International Knee Documentation Committee scores, Lysholm scores, Tegner activity scales, and KT-1000 arthrometer measurements. The two cohorts were similar in average age, acute or chronic nature of the anterior cruciate ligament rupture, and incidence of concomitant meniscal surgeries. At final followup, we found no difference in terms of Tegner, Lysholm, KT-1000, or International Knee Documentation Committee scores. Five anterior cruciate ligament reconstructions failed: three in the autograft group and two in the allograft group. Our data suggest laxity is not increased in allograft tendons compared with autografts and clinical outcome scores 3 to 6 years after surgery are similar. LEVEL OF EVIDENCE: Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Autogenous regulation of a network of bone morphogenetic proteins (BMPs) mediates the osteogenic differentiation in murine marrow stromal cells.

The expression patterns of (bone morphogenetic proteins) BMPs during fracture repair and pre-natal bone development suggest that these processes are regulated through the coordinated actions of multiple BMPs. Murine bone marrow stromal cells (MSCs) in culture provide a well recognized ex vivo system of mesenchymal stem cell differentiation in which the effects of BMPs can be examined. Studies were performed to determine if MSC differentiation is dependent on the endogenous expression of multiple BMPs and to characterize their interactions. MSCs were harvested from the bone marrow of tibiae and femora of 8 to 10-week-old male C57/B6 mice and prepared by standard methods. Osteogenic differentiation was assessed by histological assays, alkaline phosphatase enzyme activity and assays for the expression of multiple mRNAs for BMPs and osteogenic development. The role of autogenously expressed BMPs in controlling the osteogenic differentiation of marrow stromal cells in vitro was assessed in both gain-of-function and loss-of-function experiments. Gain of function experiments were carried out in the presence of exogenously added BMP-2 or -7 and loss-of-function experiments were carried out by BMP antagonism with noggin and BMP-2 antibody blockade. Osteogenic differentiation was concurrent with and proportional to increases in the expression of BMPs-2, -3, -4, -5, -6 and -8A. BMP antagonism with either noggin or BMP-2 antibody blockade inhibited osteogenic differentiation by 50% to 80%, respectively, and reduced the expression of endogenous levels of BMPs-2, -3, -5 and -8A. In contrast, antagonism induced the expression of BMP-4 and -6. The addition of rhBMP-2 or -7 enhanced osteogenic differentiation and produced a reciprocal expression profile in the endogenous BMPs expression as compared to BMP antagonism. BMP antagonism could be rescued through the competitive addition of rhBMP-2. These studies demonstrated that osteogenic differentiation was regulated by a complex network of multiple BMPs that showed selective increased and decreased expression during differentiation. They further demonstrated that BMP-2 was a central regulator in this network.