Naoki Suenaga

Application of Tissue Engineering Techniques for Rotator Cuff Regeneration Using a Chitosan-Based Hyaluronan Hybrid Fiber Scaffold

Background The current surgical procedures for irreparable rotator cuff tears have considerable limitations. Tissue engineering techniques using novel scaffold materials offer potential alternatives for managing these conditions. Hypothesis A chitosan-based hyaluronan hybrid scaffold could enhance type I collagen products with seeded fibroblasts and thereby increase the mechanical strength of regenerated tendon in vivo. Study Design Controlled laboratory study. Methods The scaffolds were created from chitosan-based hyaluronan hybrid polymer fibers. Forty-eight rabbit infraspinatus tendons and their humeral insertions were removed to create defects. Each defect was covered with a fibroblast-seeded scaffold (n = 16) or a non-fibroblast-seeded scaffold (n = 16). In the other 16 shoulders, the rotator cuff defect was left free as the control. At 4 and 12 weeks after surgery, the engineered tendons were assessed by histological, immunohistochemical (n = 2), and biomechanical (n = 6) analyses. Results Type I collagen was only seen in the fibroblast-seeded scaffold and increased in the regenerated tissue. The tensile strength and tangent modulus in the fibroblast-seeded scaffold were significantly improved from 4 to 12 weeks postoperatively. The fibroblast-seeded scaffold had a significantly greater tangent modulus than did the non-fibroblast-seeded scaffold and the control at 12 weeks. Conclusion This scaffold material enhanced the production of type I collagen and led to improved mechanical strength in the regenerated tissues of the rotator cuff in vivo. Clinical Relevance Rotator cuff regeneration is feasible using this tissue engineering technique.

Clinical results of treatment of triangular fibrocartilage complex tears by arthroscopic debridement

In order to determine indications for arthroscopic debridement and the management of triangular fibrocartilage complex (TFCC) tears, we reviewed 16 wrists retrospectively. The mean patient age was 30 years, with a range of 20 to 53 years. The follow-up period averaged 35 months. Two groups were identified: post-traumatic tears (n = 11) and degenerative tears (n = 5). The results of arthroscopic debridement were compared and analyzed based on the preoperative and postoperative evaluation of pain, range of motion, grip strength, return to work, patient acceptance, and complications. Failures were further evaluated to determine identifiable lesions or anatomic defects associated with poor results. Patients with positive ulnar variance and lunotriquentral interosseous ligament tears had a poor clinical outcome. Good results correlated with grip strength; all patients with post-traumatic TFCC tears had excellent results, while those with degenerative TFCC tears did poorly.

Donor Site Evaluation after Autologous Osteochondral Mosaicplasty for Cartilaginous Lesions of the Elbow Joint

Background One significant disadvantage of autologous osteochondral mosaicplasty (mosaicplasty) is the harvesting of osteochondral grafts from the normal articular area of the knee joint. However, the effect of harvesting grafts on knee function remains unclear. Purpose To clarify the functional effects on the donor knee of harvesting osteochondral grafts and to perform magnetic resonance imaging evaluation of donor site repair after mosaicplasty for capitellar osteochondritis dissecans in young athletes. Study Design Case series; Level of evidence, 4. Methods Eleven male competitive athletes with advanced lesions of capitellar osteochondritis dissecans underwent mosaicplasties. The surgical technique involves obtaining small-sized cylindrical osteochondral grafts from the lateral periphery of the femoral condyle at the level of the patellofemoral joint and transplanting them to osteochondral defects in the capitellum. Assessment at a mean follow-up of 26 months included local findings of the donor knees, a Lysholm knee scoring scale, International Knee Documentation Committee standard evaluation form, and magnetic resonance imaging evaluation. Results All patients returned to a competitive level of their previous sports without any donor site disturbances. Based on the Lysholm knee score and International Knee Documentation Committee evaluation form, all knees were graded as excellent and normal, respectively. The magnetic resonance imaging showed 50% to 100% defect fill in 6 of 9 patients and normal or nearly normal signals in 4 patients at the donor sites. Conclusion No adverse effects of osteochondral graft harvest on donor knee function were found after mosaicplasty for capitellar osteochondritis dissecans in young athletes. However, magnetic resonance imaging indicates that the donor site is resurfaced with fibrous tissue.

The Sauvé-Kapandji procedure for osteoarthritis of the distal radioulnar joint

The Sauvé-Kapandji procedure has been performed in 15 patients with primary and secondary osteoarthritis of the distal radioulnar joint. The average age of the patients was 45 years (range, 31-63 years). There were 12 men and 3 women. The follow-up period averaged 2 years and 11 months. Postoperative pain relief was good in all wrists. The preoperative range of motion of the wrist joint averaged 50 degrees extension and 44 degrees flexion. Forearm motion averaged 66 degrees pronation and 64 degrees supination. Postoperatively, the range of motion improved to 55 degrees extension and 51 degrees flexion at the wrist and forearm motion improved to 78 degrees pronation and 82 degrees supination. Although all wrists also showed an increased grip strength and improved range of motion over preoperative values, these did not have statistical significance. Postoperative x-ray evaluation showed an unstable proximal stump and radioulnar convergence in 12 wrists. Our clinical and x-ray film findings suggest that the Sauvé-Kapandji procedure is a satisfactory procedure for patients with osteoarthritis of the distal radioulnar joint.

Electromyographic study during isometric exercise of the shoulder in head-out water immersion

Water exercises are used for early rehabilitation programs after shoulder injury such as rotator cuff tear, yet no literature discusses the muscle activity of such rehabilitation programs in water. The purpose of this study was to analyze the electromyographic activity from 8 volunteers during isometric exercises in water and on land. Nine isometric exercises were studied: with 30 degrees, 60 degrees, and 90 degrees shoulder flexion and abduction, and 3 positions of shoulder rotation at 0 degrees abduction (both maximal internal and external rotation and mid-position). Nine parts of 6 muscles were studied: the supraspinatus, infraspinatus, subscapularis, 2 parts of the pectoralis major (clavicular and costal), 3 parts of the deltoid (anterior, middle, and posterior), and the latissimus dorsi. The electromyographic signals were low-pass filtered, full-wave rectified, and integrated for 5 seconds. The electromyographic activity was quantified as a percentage of the maximal manual muscle test. The results showed that supraspinatus activity at 90 degrees abduction significantly decreased from 22.3+/-15.8 on land to 3.9+/-3.3% manual muscle test in water (P < .01). Other muscle activities in water also decreased remarkably compared with those on land. These results provide valuable information for the safety of water exercise for early rehabilitation programs after shoulder injury such as rotator cuff tear.

A long-term follow-up of silicone-rubber interposition arthroplasty for osteoarthritis of the thumb carpometacarpal joint.

There are several surgical options for osteoarthritis (OA) of the thumb carpometacarpal (CMC) joint. This paper presents our long-term clinical and radiographic review of 12 thumbs in ten patients treated by partial trapezial excision and silicone-rubber interposition arthroplasty. The follow-up period averaged 15; three years with a ten-year minimum. Although the procedure provided early pain relief in most thumbs, all but two had mild to severe pain at follow-up. The average range of post-operative palmar abduction was 23 degrees. The average post-operative grip strength was 9.5 kg. Both tip and key pinch between thumb and index finger averaged about 50% that of normal subjects. Dislocation of the implant occurred in two joints and breakages in five. Bony erosions around the implant, which we attributed silicone synovitis, were found in four thumbs. The indications for silicone-rubber interposition arthroplasty for OA of the thumb CMC joint should be severely restricted as these produced unsatisfactory long-term results.

Treatments of osteoarthritis of the distal radioulnar joint: long-term results of three procedures.

Sixty-one wrists in 61 patients with osteoarthritis of the distal radioulnar joint treated by three consecutive procedures (20 Darrach, 25 Sauvé-Kapandji and 16 hemiresection-interposition arthroplastic procedures) were retrospectively evaluated. We preferred to perform Darrachs procedure in even the early stages of osteoarthritis of the distal radioulnar joint prior to introduction of Sauvé-Kapandji and hemirestion-interposition arthroplastic procedures. Subsequently the hemirestion-interposition arthroplasty was indicated when the triangular fibrocartilage cartilage was intact or could be reconstructed and the Sauvé-Kapandji when the triangular fibrocartilage complex could not be reconstructed or there was positive ulnar variance of more than 5 mm even though the triangular fibrocartilage complex was functional. Patients age at operation averaged 59.8 years. There were 36 men and 25 women. There were 38 primary and 23 secondary osteoarthritis cases. Post-operative pain, range of motion, grip strength, return to work status; and radiographic results were evaluated. At the five- to 14-year (average, ten years) follow-up evaluation, relief of pain from Darrach procedure was inferior to the Sauvé-Kapandji procedure and hemiresection-interposition arthroplasty although this was not statistically significant. After both the Sauvé-Kapandji procedure and hemiresection-inteposition arthroplasty, post-operative improvements in flexion and extension of the wrist had statistical significance. Post-operative improvements in pronation and supination of the forearm showed statistical significances after all procedures. Improvements of post-operative grip strength and return to an original job in the Sauvé-Kapandji procedure and hemiresection-interposition arthroplasty were statistically superior to those with a Darrachs procedure. There were many post-operative complications following the Darrachs procedure. Darrachs procedure is better indicated for severe osteoarthritic changes of the distal radioulnar joint in elderly patients. We believe the operative indications between the Sauvé-Kapandji procedure and hemiresection-interposition arthroplasty are best determined prior to surgery by the existence and status of the triangular fibrocartilage complex and the amount of the positive ulnar variance.

A new nerve block procedure for the suprascapular nerve based on a cadaveric study.

HYPOTHESIS Shoulder pain after rotator cuff repair surgery is sometimes very severe. Suprascapular nerve block (SSNB) is a method used to relieve this shoulder pain, but is not always completely effective. The purpose of this study is to develop the new effective suprascapular nerve block procedure. METHODS To obtain an effective SSNB, we investigated an anatomic lesion of the sensory branches of the SSN in 8 cadavers and developed a new procedure. We evaluated its effectiveness by recording visual analog scale (VAS) scores in 8 patients experiencing severe pain after rotator cuff repair surgery before SSNB and for up to 24 hours postoperatively. RESULTS All cadaver shoulders had 2 or 3 sensory branches that just passed the scapular notch. The branches originated from the SSN, pursued the base of the coracoid process, perforated the supraspinatus muscle, and extended toward the subacromial bursa. The average VAS score of the 8 patients postoperatively was 5.4 +/- 2.7 before SSNB and improved to 2.8 +/- 1.6 immediately after SSNB, to 1.2 +/- 0.6 at 1 hour, and to 0.8 +/- 0.8 at 4 hours. Effective pain control was achieved, and SSNB presented no complications. CONCLUSION Our SSNB method is safe and effective for pain control in patients after open cuff repair. We expect it will be a useful management tool for pain relief after rotator cuff repair in the future. LEVEL OF EVIDENCE Basic science study.

Radial osteotomy for late-stage Kienböck’s disease: WEDGE OSTEOTOMY VERSUS RADIAL SHORTENING

We have reviewed 20 patients with stage-IIIB and stage-IV Kienböcks disease in order to examine the efficacy of two forms of radial osteotomy, namely radial wedge osteotomy and radial shortening. Lateral closing wedge osteotomies and radial shortenings were carried out on 11 and nine patients, respectively. There were no preoperative differences with respect to age, gender, and radiological stage. After a mean follow-up of 29 months, all patients, in both groups, had either a good or an excellent outcome. After the lateral closing wedge osteotomy, the radioscaphoid angle significantly increased and the Ståhl index significantly decreased. Progression of the degenerative changes at the radioscaphoid joint was found in two patients in this group. By contrast, there were no significant changes in any radiological parameters after radial shortening. Both procedures gave acceptable clinical results in stage-IIIB and stage-IV Kienböcks disease.

Long-term results after primary repairs of zone 2 flexor tendon lacerations in children younger than age 6 years

In young children, methods of primary flexor tendon repair in the digital canal are controversial. The authors reviewed 12 children younger than age 6 years with zone 2 flexor tendon repairs. The mean follow-up period was 8 years. In all cases, the flexor digitorum profundus tendons were repaired according to the Kessler modified technique and the hands were immobilized by an above-elbow cast. As for postoperative complications, there were no fingers with tendon rupture and two fingers with tendon adhesion. One finger needed tenolysis. The total active motion (TAM) in the interphalangeal joints evaluated with the Strickland formula averaged 155°, and the TAM percentage averaged 89% (range 74%–100%). Eleven patients had an excellent result and one had a good result. The percentage phalangeal length averaged 99% (range 96%–100%). Functional motion and nearly normal growth of the finger can be expected after primary zone 2 flexor tendon repairs in children younger than age 6 years.