Biomechanical Characteristics of All-Suture Meniscal Repair Devices Compared With PEEK-Anchored Devices and Inside-Out Suture for Meniscal Repair: A Porcine Study.

Background: Recently, all-suture, all-inside meniscal repair devices-including devices containing flat sutures or tapes-have been introduced. Similar to those in suture anchors, these modifications may have different performance characteristics than conventional sutures and polyether ether ketone (PEEK)-anchored devices. Purpose: To compare the biomechanical characteristics of all-suture meniscal repair devices with those of a conventional PEEK-anchored device and an inside-out meniscal suture construct. Study Design: Controlled laboratory study. Methods: A total of 48 adult porcine menisci with simulated bucket-handle tears were included. Single-device repairs were performed with the SuperBall Meniscal Repair System, FiberStitch, and FAST-FIX 360 with 2 PEEK anchors, and a vertical mattress inside-out suture repair was performed using a Ti-Cron No. 2-0 braided polyethylene terephthalate suture. All specimens were preloaded (10 N) and cycled 200 times (between 10 and 50 N). Specimens surviving cyclic loading were then destructively tested. Endpoints included maximum failure load, stiffness, cyclic displacement, and failure mode. The goal was 12 successful tests in each group. Metrics between groups were compared using analysis of variance with post hoc tests to control for multiple comparisons. Results: The SuperBall (108.9 N) was significantly stronger than the FAST-FIX 360 (67.3 N) and Ti-Cron (75.2 N), and the FiberStitch (102.8 N) was significantly stronger than the FAST-FIX 360 (P≤ .01 for all). Cyclic stiffness increased during cyclic loading for all constructs (P < .001). The Ti-Cron was significantly stiffer than the SuperBall during 5 to 200 cycles (P < .001). Cyclic displacement significantly increased in all constructs during cycling (P < .001) but did not differ between devices. Failure mode varied by device: the Ti-Cron repairs failed because of suture breakage, the SuperBall and FAST-FIX 360 failed at the anchor, and the FiberStitch showed both failure modes. Conclusion: The all-suture, all-inside meniscal repair devices demonstrated superior strength to the PEEK-anchored device and the classic inside-out suture meniscal repair but no statistically significant difference in cyclic displacement.

Management of Meniscal Pathology: From Partial Meniscectomy to Transplantation.

Meniscal tears are common injuries that may result in functionally limiting pain, swelling, and mechanical symptoms. The management of meniscal pathology has evolved as surgeons' understanding of the important role the menisci play in normal knee kinematics increases. Recent emphasis on partial meniscectomy, expanding indications for meniscal repair, and the increased use of meniscal allograft transplantation have helped improve the outcomes of patients with a meniscal tear who undergo treatment. Orthopaedic surgeons should understand meniscal function, pathology, and treatment approaches.

Implantation of a Novel Cryopreserved Viable Osteochondral Allograft for Articular Cartilage Repair in the Knee.

Restoration and repair of articular cartilage injuries remain a challenge for orthopaedic surgeons. The standard first-line treatment of articular cartilage lesions is marrow stimulation; however, this procedure can often result in the generation of fibrous repair cartilage rather than the biomechanically superior hyaline cartilage. Marrow stimulation is also often limited to smaller lesions, less than 2 cm2. Larger lesions may require implantation of a fresh osteochondal allograft, though a short shelf life, size-matched donor requirements, potential challenges of bone healing, limited availability, and the relatively high price limit the wide use of this therapeutic approach. We present a straightforward, single-stage surgical technique of a novel reparative and restorative approach for articular cartilage repair with the implantation of a cryopreserved viable osteochondral allograft (CVOCA). The CVOCA contains full-thickness articular cartilage and a thin layer of subchondral bone, and maintains the intact native cartilage architecture with viable chondrocytes, growth factors, and extracellular matrix proteins to promote articular cartilage repair. We report the results of a retrospective case series of three patients who presented with articular cartilage lesions more than 2 cm2 and were treated with the CVOCA using the presented surgical technique. Patients were followed up to 2 years after implantation of the CVOCA and all three patients had satisfactory outcomes without adverse events. Controlled randomized studies are suggested for evaluation of CVOCA efficacy, safety, and long-term outcomes.

The management of meniscal pathology: from partial meniscectomy to transplantation.

The management of meniscal pathology continues to evolve as researchers gain a better understanding of the role of the meniscus in normal knee kinematics. Evidence now supports retention or transplantation of meniscal tissue to maintain homeostatic knee mechanisms because the removal of meniscal tissue changes the contact stresses and leads to structural and biomechanical changes in the articular cartilage and the subchondral plate that predisposes the knee to the development of degenerative arthritis. Advances in repair techniques, biologic adjuvants, and progressive tissue-engineering strategies are rapidly adding to the surgeon's armamentarium when dealing with meniscal injury and insufficiency. Early clinical data support many of these advanced techniques. It is helpful to explore meniscal function, pathology, and current treatment modalities, with a focus on meniscal repair and transplantation as well as adjuvants to biologic healing and future directions in this field.

Limitations and sources of bias in clinical knee cartilage research.

PURPOSE: The purpose of this study was to systematically review the limitations and biases inherent to surgical trials on the management of knee chondral defects. METHODS: A literature search of PubMed/Medline, CINAHL (Cumulative Index to Nursing and Allied Health Literature), EMBASE, and the Cochrane Central Register of Controlled Trials was conducted in September 2010 and updated in August 2011 to identify all English-language, Level I evidence, prospective, randomized controlled trials published from 1996 to present. The keyword search included the following: "autologous chondrocyte," "cartilage graft," "cartilage repair," "chondroplasty," "microfracture," "mosaicplasty," and/or "osteochondral." Nonoperative studies, nonhuman studies, ex vivo studies, non-knee studies, and/or studies with follow-up of less than 1 year were excluded. A systematic review was performed on all included studies, and limitations and/or biases were identified and quantitated. RESULTS: Of 15,311 citations, 33 abstracts were reviewed and 11 prospective, randomized controlled trials were included. We identified 9 major limitations (subject age, subject prior surgery, subject duration of symptoms, lesion location, lesion size, lesion number, procedure selection, procedure standardization, and limited histologic analysis) and 7 common biases (selection, performance, transfer, nonresponder, detection, publication, and study design). CONCLUSIONS: Level I therapeutic studies investigating the surgical management of human knee cartilage defects have substantial identified biases and limitations. This review has limitations because other classifications of bias or limitation exist. Optimal management of cartilage defects is controversial, and future rigorous research methods could minimize common biases through strict study design and patient selection criteria, larger patient enrollment, more extended follow-up, and standardization of clinical treatment pathways. LEVEL OF EVIDENCE: Level I, systematic review of Level I studies.

Supplemental tibial fixation for anterior cruciate ligament reconstruction.

This report describes transosseous backup suture fixation for anterior cruciate ligament (ACL) grafts of all varieties, used to distally augment proximal screw fixation in the tibia. Using a simple suture configuration, this method secures the ACL graft to the tibial cortex in conjunction with a proximal interference screw. The technique is applicable for all graft configurations, including allograft, autograft, bone, and both 2- and 4-strand soft-tissue grafts. The described technique is intended to be used for secondary or backup fixation of the graft in the tibial tunnel and not as primary fixation. This construct can be reproducibly created, making use of the sutures that are typically present on the graft after the interference screw is placed. This technique for backup tibial fixation precludes the need for external hardware, which in many instances may be symptomatically proud. Furthermore, use of this technique may represent a potential cost savings because no additional devices or equipment is used or purchased. This technique is simple, fast, and inexpensive, making use of available constructs to enhance the security of graft fixation during ACL reconstruction.

Focal anatomic patellofemoral inlay resurfacing: theoretic basis, surgical technique, and case reports.

Prosthetic patellofemoral inlay resurfacing is a novel treatment concept for degenerative and focal arthrosis of the patellofemoral joint. The theoretic basis of this type of arthroplasty entails recreating ambient anatomy based upon intraoperative topographic mapping. The implant is intrinsically stable by virtue of the inset position relative to the surrounding joint surface. Articular resurfacing, rather than traditional replacement arthroplasty, represents an extension of the concepts of biologic joint restoration. Early results have shown great efficacy. This surgery may be appropriate for a wide variety of indications, including younger patients and those with focal patellofemoral disease concurrent with morphologic or alignment abnormalities.

Clinical, histologic, and radiographic outcomes of distal femoral resurfacing with hypothermically stored osteoarticular allografts.

BACKGROUND: Fresh osteoarticular allograft transplantation has a long history of clinical success. These grafts have typically been implanted less than 1 week from donor asystole. HYPOTHESIS: Osteoarticular allografts stored 4 to 6 weeks represent a viable alternative to treat full-thickness cartilage and osteochondral defects of the distal femur as measured by clinical, histologic, and magnetic resonance imaging (MRI) criteria. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Osteoarticular allografts were implanted after a mean graft storage time (at 4 degrees C) of 36 days (range, 28-43). Sixty-seven patients received massive hypothermically stored osteoarticular allografts. Ten knees in 8 of these patients underwent second-look arthroscopic evaluation and biopsy at a mean of 40 months (range, 23-60) after implantation. Clinical assessment was performed using multiple outcome measures and sequential MRI evaluations. Biopsy specimens were obtained from the graft as well as from native articular cartilage at the time of second-look arthroscopy for histologic analysis. RESULTS: The mean International Knee Documentation Committee scores were as follows: preoperative, 27 (range, 9-55); postoperative, 79 (range, 56-99); P = .002. The mean Lysholm scores were as follows: preoperative, 37 (range, 12-47); postoperative, 78 (range, 55-90); P = .002. The mean Short Form-36 physical scores were as follows: preoperative, 38 (range, 24-55); postoperative, 51 (range, 39-61); P = .002. The mean Tegner scores were as follows: preoperative, 4.3 (range, 1-9); postoperative, 5.3 (range, 4-7); P = .16. The mean International Cartilage Repair Society score at follow-up was 10 (nearly normal) (range, 7-11). The mean modified Outerbridge scores were as follows: preoperative, 4.3 (range, 3-5); postoperative, 0.6 (range, 0-1); P = .002. The mean graft and native cartilage cellular density and viability were not statistically different. CONCLUSIONS: Fresh-stored osteoarticular grafts for full-thickness articular surface defects of the distal femur appear to offer a viable biological method to restore knee function. Our study suggests that osteoarticular grafts stored in cell culture medium at 4 degrees C for 4 to 6 weeks provide successful short-term clinical outcomes.

Mobile superior glenoid labrum: a normal variant or pathologic condition?

BACKGROUND: Arthroscopic differentiation between a pathologic superior labrum anterior posterior lesion and a normal anatomic variant may be difficult. HYPOTHESIS: Various anatomic patterns exist that systematically characterize superior biceps-labral configurations. One variant involves a mobile superior labrum with exposed articular cartilage on the superior glenoid tubercle. The authors seek to demonstrate that this is nonpathologic. STUDY DESIGN: A prospective, consecutive descriptive anatomic study with 1-year clinical follow-up of a subgroup with an identified mobile superior labrum. METHODS: A total of 191 consecutive patients were prospectively evaluated arthroscopically to quantify the dimensions of the labrum and articular cartilage on the supraglenoid tubercle. RESULTS: A subgroup of 49 patients was identified with articular cartilage on the supraglenoid tubercle, a mobile labrum, and no fibrous tearing or evident injury in this region. In postoperative follow-up, only 1 (2.0%) of these patients was clinically symptomatic in the region of the superior labrum-biceps origin. CONCLUSIONS: Indication for repair of a mobile superior glenoid labrum must be carefully addressed in the context of normal anatomic morphologic variability. The labral and supraglenoid tubercle morphology was noted to be highly variable. CLINICAL RELEVANCE: Patients with mobile labral tissue overlying intact articular cartilage, and no evidence of trauma, are not candidates for repair.

The 7-o'clock posteroinferior portal for shoulder arthroscopy.

BACKGROUND: Access to the inferior glenohumeral joint of the shoulder is very limited through the traditional 2- or 3-o'clock anterior portals. HYPOTHESIS: The 7-o'clock posteroinferior portal offers an excellent alternative approach. STUDY DESIGN: Descriptive anatomic study. METHODS: Six paired cadaveric shoulders were used to arthroscopically develop and test a 7-o'clock posteroinferior portal. The distances between the portal and the subscapular and axillary nerves were measured with the arm in six different positions, combining flexion, extension, abduction, and adduction. RESULTS: The distance from the 7-o'clock posteroinferior portal to the axillary nerve was 39 +/- 4 mm and to the suprascapular nerve was 28 +/- 2 mm. There was no statistically significant nerve-to-portal differential distance when the arm was placed in flexion, extension, abduction, or adduction. The inside-to-outside technique produced a 7-o'clock posteroinferior portal approximately 5 mm further from both the axillary and suprascapular nerves than did the outside-to-inside method. The angle of divergence from the 7-o'clock posterior portal skin incision to the axillary nerve was 47 degrees and to the suprascapular nerve was 33 degrees. CONCLUSIONS: The 7-o'clock portal affords safe, direct working access to the inferior capsular recess of the glenohumeral joint. CLINICAL RELEVANCE: The 7-o'clock portal is a safe and effective technique for use by shoulder surgeons.