F. Alan Barber

A Prospective, Randomized Evaluation of Acellular Human Dermal Matrix Augmentation for Arthroscopic Rotator Cuff Repair

PURPOSE To prospectively evaluate the safety and effectiveness of arthroscopic acellular human dermal matrix augmentation of large rotator cuff tear repairs. METHODS A prospective, institutional review board-approved, multicenter series of patients undergoing arthroscopic repair of 2-tendon rotator cuff tears measuring greater than 3 cm were randomized by sealed envelopes opened at the time of surgery to arthroscopic single-row rotator cuff repair with GraftJacket acellular human dermal matrix (Wright Medical Technology, Arlington, TN) augmentation (group 1) or without augmentation (group 2). Preoperative and postoperative functional outcome assessments were obtained by use of the American Shoulder and Elbow Surgeons (ASES), Constant, and University of California, Los Angeles scales. Gadolinium-enhanced magnetic resonance imaging (MRI) evaluation of these repairs was obtained at a mean of 14.5 months (range, 12 to 24 months). Adverse events were recorded. RESULTS There were 22 patients in group 1 and 20 in group 2 with a mean age of 56 years. The mean follow-up was 24 months (range, 12 to 38 months). The ASES score improved from 48.5 to 98.9 in group 1 and from 46.0 to 94.8 in group 2. The scores in group 1 were statistically better than those in group 2 (P = .035). The Constant score improved from 41.0 to 91.9 in group 1 and from 45.8 to 85.3 in group 2. The scores in group 1 were statistically better than those in group 2 (P = .008). The University of California, Los Angeles score improved from 13.3 to 28.2 in group 1 and from 15.9 to 28.3 in group 2 (P = .43). Gadolinium-enhanced MRI scans showed intact cuffs in 85% of repairs in group 1 and 40% in group 2 (P < .01). No adverse events were attributed to the presence of the matrix grafts. CONCLUSIONS Acellular human dermal matrix augmentation of large (>3 cm) cuff tears involving 2 tendons showed better ASES and Constant scores and more frequent intact cuffs as determined by gadolinium-enhanced MRI. Intact repairs were found in 85% of the augmented group and 40% of the nonaugmented group (P < .01). No adverse events related to the acellular human dermal matrix were observed. LEVEL OF EVIDENCE Level II, lesser-quality randomized controlled trial.

Preliminary results of an absorbable interference screw

A randomized, prospective multicenter comparison was done of a bioabsorbable interference screw (Bioscrew; Linvatec Corp, Largo, FL) made from poly L-lactic acid and a metal interference screw produced by the same company. Assignment was randomized by sealed envelopes. A total of 110 patients underwent arthroscopic patellar tendon autografts. A minimum 12 months follow-up is available on 85 patients (mean 19 months, range 12 to 33) including 42 with Bioscrews and 43 with metal screws. There were 56 male and 29 female patients. The average age was 29 years (16 to 50 years). Tourniquet times and associated surgical findings were similar for the two groups. Postoperative Tegner and Lysholm scores were not statistically different between the two groups. KT tests at 1 year showed an average 20-lb laxity of 1.8 mm for the Bioscrew and 1.2 mm for the metal screw groups. The average 1-year KT maximum manual side-to-side difference was 1.6 mm for Bioscrews and 1.6 mm for metal screws. A pivot shift was absent in 83% of Bioscrews and 90% of metal screws at follow-up. Six of 85 Bioscrews inserted (7%) broke on insertion (all were 7-mm diameter screws at the femoral site). No additional fixation was required in four cases. In two, the broken screw was replaced. No lytic bone changes or tunnel widening were found with any Bioscrew. One metal screw had tibial tunnel widening. No statistical difference was found between the Bioscrew and the metal screw groups. Short-term data support the conclusion that the Bioscrew is a reasonable alternative to metal interference screws.

Rotator cuff repair healing influenced by platelet-rich plasma construct augmentation.

PURPOSE To assess the effect of platelet-rich plasma fibrin matrix (PRPFM) construct augmentation on postoperative tendon healing as determined by magnetic resonance imaging (MRI) and clinical outcome of arthroscopic rotator cuff repair. METHODS A comparative series of patients undergoing arthroscopic rotator cuff repair was studied. Two matched groups of patients (20 each) were included: rotator cuff repairs without PRPFM augmentation (group 1) and rotator cuff repairs augmented with 2 sutured platelet-rich plasma (PRP) constructs (group 2). A single-row cuff repair to the normal footprint without tension or marrow vents was performed by a single surgeon. Postoperative rehabilitation was held constant. Postoperative MRI scans were used to evaluate rotator cuff healing. Outcome measures included American Shoulder and Elbow Surgeons, Rowe, Single Assessment Numeric Evaluation, Simple Shoulder Test, and Constant scores. RESULTS We followed up 40 patients (2 matched groups with 20 patients each) with a mean age of 57 years (range, 44 to 69 years) for a mean of 31 months (range, 24 to 44 months). Postoperative MRI studies showed persistent full-thickness tendon defects in 60% of controls (12 of 20) and 30% of PRPFM-augmented repairs (6 of 20) (P = .03). Of the control group tears measuring less than 3 cm in anteroposterior length, 50% (7 of 14) healed fully, whereas 86% of the PRPFM group tears measuring less than 3 cm in anteroposterior length (12 of 14) healed fully (P < .05). There was no significant difference between groups 1 and 2 in terms of American Shoulder and Elbow Surgeons (94.7 and 95.7, respectively; P = .35), Single Assessment Numeric Evaluation (93.7 and 94.5, respectively; P = .37), Simple Shoulder Test (11.4 and 11.3, respectively; P = .41), and Constant (84.7 and 88.1, respectively; P = .19) scores. The Rowe scores (84.8 and 94.9, respectively; P = .03) were statistically different. CONCLUSIONS The addition of 2 PRPFM constructs sutured into a primary rotator cuff tendon repair resulted in lower retear rates identified on MRI than repairs without the constructs. Other than the Rowe scores, there was no postoperative clinical difference by use of standard outcome measures. LEVEL OF EVIDENCE Level III, case-control study.

Meniscus repair rehabilitation with concurrent anterior cruciate reconstruction

Meniscal repair is preferable to meniscectomy because of the recognized benefits of the meniscus and the consequences of its loss. The most appropriate rehabilitation program after meniscus repair is unclear. Many meniscus repairs occur in association with anterior cruciate ligament (ACL) reconstructions. An accelerated program permitting early full weight bearing, unrestricted motion, and no limitations on pivoting sports after the resolution of the postoperative effusion and full motion is established encourages patients and surgeon acceptance of the meniscus repair. To evaluate the success of meniscus repair in this accelerated rehabilitation program, a consecutive series of 63 patients with 65 meniscus tears undergoing arthroscopic meniscus repair were followed for a minimum of 2 years. There were seven failures (11%) at an average follow up of 38 months. The average patient age was 26 (range, 13 to 44). Arthroscopic relooks were done in 26%. Successful meniscal healing occurred in 92% of repairs done with ACL reconstructions, but only 67% of meniscus repairs performed in ACL-deficient knees, and 67% of meniscus repairs done in stable knees with no ACL injury. There was no statistical difference in the failures for acute and chronic meniscus tears, nor in the age of the patient undergoing the meniscal repair. Published rehabilitation protocols differ considerably on the three main issues of immobilization, weight bearing, and return to pivoting sports. These data show a meniscus repair success rate consistent with other published series. No modification of an ACL reconstruction accelerated rehabilitation program is needed for meniscus repairs performed in conjunction with the reconstruction.

Suture anchor failure strength-an in vivo study

Suture anchors are increasingly used to secure tendons or ligaments to bone. These devices are applicable for arthroscopic shoulder stabilization and rotator cuff repair. This study reports the in vivo characteristics of four anchors, including one absorbable anchor composed of poly-L-lactic acid. Failure strength and method of failure were recorded for these anchors as a function of time. Samples of four anchors [Mitek G2, Zimmer Statak, Acufex TAG wedge, and the absorbable Arthrex expanding suture plug (ESP)] were implanted into ram femurs and harvested at intervals. Each bone-anchor-suture system was stressed to failure. The failure force and failure method was recorded. Mitek G2 and Statak suture anchors failed consistently at 30 pounds by suture breakage. They had no implantation difficulties. The TAG wedge exhibited suture pull-out and implant flipping at insertion. The TAG wedge failed by suture cut-out, anchor pull-out, and suture breakage. Its average failure strength was initially 16 pounds, but increased to 28 pounds at 2 weeks and reached the 30-pound level by 4 weeks. The ESP poly-L-lactic acid anchors experienced implantation breakage in 20% because of their greater length and composition. At pull-out testing, the ESP failed by suture cut-out, anchor pull-out, and suture breakage. Failure strength was initially 27 pounds, was 17 pounds at 2 weeks, and increased to 30 pounds by 6 weeks. The absorbable ESP does not have initial pull-out strength comparable with the Mitek and Statak suture anchors but does achieve this strength by 6 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Biceps tendon and superior labrum injuries: decision making.

Although the anatomy of the biceps tendon and the restraining structures within the rotator interval are well defined, biceps function is not clearly understood. Biceps pathology is often associated with rotator cuff disease. Although careful clinical examinations along with diagnostic testing can accurately identify patients with biceps pathology, arthroscopy is extremely valuable in the diagnosis and treatment of biceps pathology. Surgical treatment options for biceps pathology include decompression, débridement, tenotomy, and tenodesis. Several factors must be considered in this decision. The most important factors when deciding between tenodesis or tenotomy are the activity expectations of the patient, cosmesis, patient compliance, associated pathology, and patient age. Those older than 60 years tolerate a tenotomy with the fewest adverse effects. Various arthroscopic tenodesis techniques exist, including an interference screw in bone, suture anchor fixation, and suture to adjacent tissue fixation. An open subpectoral tenodesis is another option and appropriate for a retracted biceps rupture or when the biceps disease extends distal to the bicipital groove. A superior labrum anterior and posterior (SLAP) lesion at the attachment site of the biceps tendon to the superior glenoid labrum is uncommon. Clinically significant SLAP lesions are found in about 5% of all shoulder arthroscopies and may be mistaken for normal superior labral variations. Clinical examinations and diagnostic imaging tests for SLAP lesions are often unreliable, and the ultimate diagnostic confirmation is made by arthroscopy. Surgical treatment is focused on the reattachment of the unstable biceps-labral complex.

The relationship of suture anchor failure and bone density to proximal humerus location: a cadaveric study.

The purpose of this study was to evaluate spatial variations in the pullout strength of a suture anchor in the proximal humerus, and to correlate any differences with the local mineral density (BMD). Screw-type suture anchors threaded with wire sutures were inserted at six different anchor insertion sites in 11 human cadaveric humeri (average age, 80 years). Load to failure tests with forces applied in line with the axis of insertion were performed, and bone mineral density measurements were then made at these sites. The greater tuberosity showed anterior and posterior differences in anchor pullout force (P = .03), with the posterior portion showing higher strength (154 N) than the anterior area (96 N). Neither the lesser tuberosity (185 N anterior area and 177 N posterior area) nor the humeral neck (170 N anterior and 174 N posterior area) showed significant differences, and they were statistically equivalent to the greater tuberosity. There was no demonstrable difference in BMD at any of the six sites tested. There is no support for the hypothesis that significant differences in load to failure exist among the lesser tuberosity, humeral neck, and greater tuberosity. Also, there is no support for the hypothesis that the load to failure variations for the proximal humerus are dependent on BMD. Bone mineral density appears to have no correlation with the pullout strength of a screw-type suture anchor.

Suture anchor strength revisited

The rapid proliferation of suture anchors continues. Our prior report on the pullout strength of 14 different anchors is supplemented by a similar test conducted on 8 additional anchors. Comparative data on modes of failure and failure strengths (ultimate loads to failure) for these new devices are compared statistically with the previously tested anchors. In a fresh never-frozen porcine femur model, 10 samples of each of the additional anchors tested were threaded with stainless steel sutures and inserted into three different test areas (diaphyseal cortex, metaphyseal cortex, and a cancellous trough). Tensile stress parallel to the axis of insertion was applied at a rate of 12.5 mm/s by an Instron 1321 testing machine (Instron Corp, Canton, MA) until failure and mean anchor failure strengths calculated. The anchors tested were the Mitek G2 as a control, miniMitek, Mitek Superanchor, Mitek Rotator Cuff anchor (Mitek Products, Westwood, MA), Innovasive Devices Radial Osteal Compression device (Innovasive Devices, Hopkinton, MA), Arthrex Fastak (Arthrex Inc, Naples, FL), Arthrotek miniHarpoon (Arthrotek, Warsaw, IN), Orthopedic Biosystems PeBA 3 and PeBA 5 (Orthopedic Biosystems, Scottsdale, AZ), and AME 5.5 screw (American Medical Electronics, Richardson, TX). Failure mode (anchor pullout, suture eyelet cut out, or wire breakage) was generally consistent for each anchor type. The size of insertion hole is clinically important and each anchors performance was evaluated as a function of its minor diameter or drill hole. For screw anchors, the larger the minor diameter of the screw, the higher the mean failure strengths in all three test areas (P = .001). However, larger drill holes for non-screw anchors resulted in lower mean failure strengths in cancellous bone (P = .03) and diaphyseal cortex (P < .005).

Ultimate Tensile Failure Loads of a Human Dermal Allograft Rotator Cuff Augmentation

PURPOSE The purpose of this study was to examine the failure mode of supraspinatus tendon repairs with and without human dermal allograft augmentation. METHODS Ten matched pairs of human cadaveric supraspinatus muscles and tendons were detached from their greater tuberosity insertions and then reattached with four simple sutures in 2 suture anchors as a control group. One shoulder from each matched pair was augmented with human dermal allograft secured to the humerus and the supraspinatus tendon using the same sutures and suture anchors. Additional interrupted mattress sutures secured the edges of the dermal allograft to the supraspinatus tendon. Each construct was preloaded at 10 N and then cyclically loaded between 10 N and 100 N for 10 cycles at 20 N/s followed by destructive testing at 33 mm/s. Force and displacement were recorded. RESULTS The mean failure strengths for the control and augmented constructs were 273 +/- 116 N and 325 +/- 74 N, respectively (P = .047). No significant displacement occurred during the cyclic phase, and no anchors failed. These constructs failed by 2 different mechanisms: tendon-suture interface failure (8/10 non-augmented repairs and 6/10 augmented repairs) and suture breakage (2/10 non-augmented repairs and 4/10 augmented repairs). CONCLUSIONS This examination of the failure characteristics and ultimate failure load of supraspinatus tendon tears augmented with GraftJacket (Wright Medical Technology, Arlington, TN) supported the study hypothesis that a human dermal allograft significantly increases the strength of a repaired tendon. CLINICAL RELEVANCE The human dermal allograft can be expected to significantly increase the initial strength of a rotator cuff repair.

Tendon graft substitutes-rotator cuff patches.

Over the past few years, many biologic patches have been developed to augment repairs of large or complex tendon tears. These patches include both allograft and xenografts. Regardless of their origins, these products are primarily composed of purified type I collagen. Many factors should be considered when choosing an augmentation patch including tissue origin, graft processing, cross-linking, clinical experience, and physical properties. The purpose of this article is to familiarize the sports medicine community with several tendon augmentation grafts: GraftJacket (Wright Medical Technology, Arlington, TN), CuffPatch (Organogenesis, Canton, MA, licensed to Arthrotek, Warsaw, IN), Restore (Depuy, Warsaw, IN), Zimmer Collagen Repair (Permacol) patch (Tissue Science Laboratories Covington, GA, licensed to Zimmer, Warsaw, IN), TissueMend (TEI Biosciences, Boston, MA, licensed to Stryker Howmedica Osteonics, Kalamazoo, MI), OrthoADAPT (Pegasus Biologics, Irvine, CA), and BioBlanket (Kensey Nash, Exton, PA).