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Biomedical subjects

David A Coons

Publications and source records attributed to David A Coons.

10 recordsLinked to original sources

Thermal medial retinaculum shrinkage and lateral release for the treatment of recurrent patellar instability.

PURPOSE: To study a technique of medial retinacular thermal shrinkage and evaluate the clinical effectiveness of this technique. TYPE OF STUDY: Nonrandomized prospective case series. METHODS: A consecutive series of patients with recurrent patellar instability treated with arthroscopic lateral release and medial thermal retinaculum shrinkage using a monopolar radiofrequency probe was assessed subjectively by visual analog scale and both preoperatively and postoperatively by physical examination and Lysholm and Fulkerson knee scores. RESULTS: We evaluated 53 knees with an average follow-up of 53 months (range, 24 to 88 months). The mean Lysholm and Fulkerson scores improved from 45 and 41 to 81 and 82, respectively. Subjectively, 48 of 53 knees (90%) were reported as excellent or good. The average visual analog scale score was 8 out of 10. Five patients failed because of recurrent dislocation (9% recurrence). Additional stabilization procedures were performed in 4 patients. CONCLUSIONS: Medial shrinkage using monopolar thermal energy is effective in treating recurrent patellar instability. Our results were comparable with prior studies using suture plication. The technique avoids additional incisions and decreases operative time. LEVEL OF EVIDENCE: Level IV, therapeutic prospective cohort study.

Adolescent↗

Midterm results of meniscal repair using the BioStinger meniscal repair device.

PURPOSE: The purpose of this study was to evaluate the midterm healing rate and any adverse events from meniscus repair using the BioStinger meniscus repair device (Linvatec, Largo, FL). METHODS: A retrospective review of a consecutive series of meniscal repairs performed by a single surgeon using the BioStinger was conducted. The BioStinger is cannulated, made of molded poly L-lactic acid, and inserted over a needle into the meniscus tissue. Clinical results and adverse events were noted, and Lysholm, Tegner, Cincinnati, and International Knee Documentation Committee (IKDC) activity scores were obtained on all patients. RESULTS: Forty-one patients underwent 41 meniscal repairs with an average follow-up of 38.6 months (range, 24 to 69 months); 35 meniscus repairs were performed in conjunction with anterior cruciate ligament reconstruction and 6 in stable knees. Tears repaired were peripheral, posterior horn tears with an average length of 2 cm. Clinical evidence of meniscal healing was observed in 95% at the time of last follow-up. Six second-look arthroscopies were performed and 2 failures were found. All other patients were symptom free. At follow-up, the mean Tegner score was 6.1 (2.8 preoperative), IKDC activity score was 3.3 (2.1 preoperative), Lysholm score was 90.6 (48.7 preoperative), and the mean Cincinnati score was 86.7 (41.3 preoperative). Four patients had peripheral migration of the device without skin tenting or perforation; 3 underwent removal of the BioStinger from the soft tissues and the other resolved after 12 months. CONCLUSIONS: The midterm clinical success rate was 95% using the BioStinger device. Adverse events were observed in few cases. LEVEL OF EVIDENCE: Level IV, cases series.

Absorbable Implants↗

Tendon augmentation grafts: biomechanical failure loads and failure patterns.

PURPOSE: The purpose of this study was to determine the load to failure strengths and modes of failure of various commercially available tendon augmentation xenografts and allografts. TYPE OF STUDY: Experimental laboratory study. METHODS: GraftJacket (Wright Medical Technology, Arlington, TN), CuffPatch (Arthrotek, Warsaw, IN), Restore (Depuy, Warsaw, IN), Permacol (Tissue Science Laboratories, Covington, GA; licensed to Zimmer, Warsaw, IN), and TissueMend (TEI Biosciences, Boston, MA; licensed to Stryker Howmedica Osteonics, Kalamazoo, MI) measuring 2 x 5 cm were hydrated according to manufacturers guidelines, a horizontal mattress stitch 5-mm wide was placed 5 mm from the narrow edge of the graft. Tensile loads to failure were applied on the suture while an Instron machine held the graft material and mean loads to failure of the suture graft construct were obtained and modes of graft failure noted. RESULTS: The mean loads to failure were obtained: GraftJacket thin (157 N), GraftJacket MaxForce (182 N), GraftJacket Extreme (229 N), CuffPatch (32 N), Restore (38 N), Permacol (128 N), and TissueMend (70 to 76 N). Failure occurred principally by suture pull-through in all specimens and patterns tended to vary by implant type. CuffPatch and TissueMend tended to fail by isthmus pullout, whereas Restore and Graft jacket failed by end pullout. The tissues were statistically stratified into four groups depending on the material. Human skin (GraftJacket) was the strongest followed by porcine skin (Permacol) and bovine skin (TissueMend). Both in turn were stronger than the porcine small intestine submucosa (Restore and CuffPatch) (P < 0.001). CONCLUSIONS: Suture retention can be reliably tested with a narrow range of standard error utilizing this testing methodology. Skin has higher loads to failure than intestine submucosa. Failure modes differed significantly among the implant types, suggesting that suturing methods for each implant should be considered independently before use. These data cannot be interpreted to suggest that one graft material is clinically superior to another. Rather, each has different properties that the surgeon should recognize when considering their use. CLINICAL RELEVANCE: These grafts have been used as augmentations and substitutions in tendon repairs and as a material for interpositional arthroplasty. These data show that the successful use of these materials requires adequate separation of the fixation sutures and provides an understanding of how each material will fail if subjected to excessive loading during the rehabilitation period.

Bioprosthesis↗

Sutures and suture anchors--update 2006.

PURPOSE: To evaluate recently introduced sutures and suture anchors for single pull load to failure strength and failure mode. METHODS: Suture anchors were tested in fresh porcine metaphyseal cortex and cancellous troughs with the use of an established protocol. An Instron machine applied tensile loads parallel to the axis of insertion at a rate of 12.5 mm/sec until failure, and mean anchor failure strengths were calculated. The mode of failure (anchor pull-out, suture eyelet cut-out, or suture failure) was recorded. Anchors tested included the BioRaptor 2.9, BioZip, Super Revo, Impact, Allograft cortical anchor, SpiraLok, Herculon, AxyaLoop titanium anchors 3, 5, and 6.5 mm, AxyaLoop bioabsorbable anchors 3, 5, and 6.5, ParaFix titanium anchors 3, 5, and 6.5, ParaSorb BioAnchors 3, 5.5, and 6.5, and Bio-Corkscrew FT. Sutures were also tested through an established protocol for load to failure. Sutures tested consisted of Orthocord, Ultrabraid (White and CoBraid), ForceFiber, Hi-Fi, MagnumWire, and Maxbraid Polyethylene Plus. RESULTS: Mean failure loads were as follows: BioRaptor 238 N, BioZip 366 N, double-loaded Super Revo 486 N, triple-loaded Super Revo 362 N, Impact 202 N, Allograft cortical anchor 240 N, SpiraLok 289 N, Herculon 819 N, AxyaLoop titanium anchors 3.0 (335 N), 5.0 (485 N), and 6.5 mm (465 N), AxyaLoop bioabsorbable anchors 3 (143 N), 5 (395 N), and 6.5 (369 N), ParaFix titanium anchors 3 (335 N), 5 (485 N), and 6.5 (465 N), ParaSorb BioAnchors 3 (143 N), 5.5 (395 N), and 6.5 (369 N), and Bio-Corkscrew FT (260 N). The sutures all broke at the mid point of their tested strands away from the grips. Mean suture strength for No. 2 Orthocord was 92 N; for No. 2 Ultrabraid CoBraid and White, strengths were 265 N and 280 N, respectively; strength for No. 2 Force Fiber was 289 N, for No. 2 Hi-Fi 250 N, for No. 2 MagnumWire 303 N, and for No. 2 Maxbraid Polyethylene Plus 256 N. CONCLUSIONS: Newer suture products showed significant improvements in load to failure values when compared with braided polyester sutures. Higher load to failure values continue to be seen in metal versus biodegradable anchors and in screw-type versus nonscrew designs. CLINICAL RELEVANCE: Surgeons who prefer stronger sutures now have several high-strength suture options from which to choose. Most of the new anchors tested performed very well.

Animals↗

Meniscal repair with the RapidLoc meniscal repair device.

BACKGROUND: The RapidLoc is an all-inside, self-adjusting, flexible meniscal repair device that combines a suture with an anchor component and, by using a reinforced sliding knot, allows for tightening to compress and hold the repaired meniscal segments. The purpose of this study was to evaluate the clinical success of the RapidLoc device. METHODS: A prospective consecutive series of meniscal repairs performed with the RapidLoc device was studied. Lysholm, Tegner, Cincinnati, IKDC (International Knee Documentation Committee) activity scores, clinical examination findings, and adverse events were recorded on all patients. Associated procedures were recorded. An accelerated postoperative rehabilitation program was followed, independent of whether anterior cruciate ligament (ACL) surgery was also performed. RESULTS: A total of 32 patients underwent 32 meniscal repairs, with an average follow-up of 31 months (18 to 48 months). In all, 23 repairs were done in conjunction with ACL reconstruction, and 9 repairs were carried out in stable knees. Repairs were made to 25 medial menisci and 7 lateral menisci. Tears repaired consisted of peripheral longitudinal tears with an average length of 2 cm (range, 15 to 30 mm). Four failures (12.5%) were arthroscopically documented. Clinical success occurred in 87.5% at the time of last follow-up. At follow-up, mean Tegner score was 5.1 (2.8 preoperative), IKDC activity score was 3.1 (1.8 preoperative), Lysholm score was 93.6 (48.4 preoperative), and mean Cincinnati score was 88.1 (43.7 preoperative). The most common adverse event was cutting of the suture during RapidLoc insertion. One patient had excoriation and grooving of the medial femoral condyle associated with failed repair. Another patient developed a postoperative infection. CONCLUSIONS: The early clinical success rate was 87.5% with the RapidLoc device. Chondral grooving was observed in a single case. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Arthroscopy↗

Triple-loaded single-anchor stitch configurations: an analysis of cyclically loaded suture-tendon interface security.

PURPOSE: This study evaluated the strength and suture-tendon interface security of different suture configurations from triple-suture-loaded anchors. METHODS: A juvenile bovine infraspinatus tendon was detached and repaired by use of 4 different suture combinations from 2 suture anchors: 3 simple sutures in each anchor (ThreeVo anchor; Linvatec, Largo, FL); 2 peripheral simple stitches and 1 central horizontal mattress suture passed deeper into the tendon, creating a larger footprint (bigfoot-print anchor); 2 peripheral simple stitches with 1 central horizontal mattress stitch passed through the same holes as the simple sutures (stitch-of-Burns); and 2 simple stitches (TwoVo anchor; Linvatec). The constructs were cyclically loaded between 10 N and 180 N for 3,500 cycles and then destructively tested. The number of cycles required to create a 5-mm gap and a 10-mm gap and the ultimate load to failure and failure mode were recorded. RESULTS: The ThreeVo anchor was strongest and most resistant to cyclic loading (P < .01). The TwoVo anchor was least resistant to cyclic loading. The stitch-of-Burns anchor was more resistant to cyclic loading than both the bigfoot-print anchor and the TwoVo anchor (P < .03). The ThreeVo, stitch-of-Burns, and TwoVo anchors were stronger than the bigfoot-print anchor (P < .05). CONCLUSIONS: Three simple sutures in an anchor hold better than two simple sutures. Three simple sutures provide superior suture-tendon security than combinations of one mattress and two simple stitches subjected to cyclic loading. A central mattress stitch placed more medially than two peripheral simple stitches (bigfoot-print anchor) configured to enlarge the tendon-suture footprint was not as resistant to cyclic loading or destructive testing as three simple stitches (ThreeVo anchor). CLINICAL RELEVANCE: Placing a central mattress stitch more medially than 2 peripheral simple stitches to enlarge the tendon-suture footprint was not as resistant to cyclic loading or destructive testing as 3 simple stitches.

Animals↗

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).

Arthroscopy↗

Shoulder arthritis in the young adult: arthroscopy to arthroplasty.

Young adult patients with shoulder arthritis present challenging treatment decisions for the orthopaedic surgeon. Patients treated with shoulder arthroplasty have the youngest average age of all patients who undergo joint arthroplasty. However, in the young, active patient or in those without advanced disease, joint arthroplasty may not be appropriate. Arthroscopic treatment or interposition arthroplasty may provide symptomatic relief without radically compromising future procedures.

Arthritis↗

Arthroscopic osteochondral autografting.

Arthroscopic osteochondral autografting is indicated for unipolar, full thickness articular cartilage lesions between 1 and 2.5 cm in diameter. A stable properly aligned knee is important to a good outcome. This procedure should not be performed in the presence of generalized osteoarthritis. Arthroscopic osteochondral autografting allows the restoration of hyaline articular cartilage with zonal matching of the graft. It is cost-effective, can be performed on an outpatient basis, and results in durable resurfacing with excellent long-term results.

Arthroscopy↗