Yasuhiro Ozasa

Functional outcomes after arthroscopic treatment of lateral epicondylitis

BackgroundThe purpose of this study was to evaluate surgical outcomes of arthroscopic débridement for lateral epicondylitis using a validated, patient-assessed scoring system as well as conventional outcome measures. We also wanted to identify potential predictive factors that may be associated with the outcomes.MethodsA total of 20 elbows in 18 patients with chronic lateral epicondylitis who underwent arthroscopic surgery were included. There were nine men and nine women with a mean age of 54 years (range 42–71 years). Operative treatment consisted of débridement of the extensor carpi radialis brevis (ECRB) origin and resection of the radiocapitellar synovial plica interposed in the joint. Outcomes were assessed using a patient rating, visual analogue scale (VAS) pain score, the Japanese Orthopaedic Association (JOA) elbow score, and the Disability of the Arm, Shoulder, and Hand (DASH) questionnaire. The average length of follow-up was 28 months (range 24–40 months).ResultsAfter surgery, according to the patients’ reports, 14 of 20 elbows were much better, and 6 elbows were better. A mean preoperative VAS pain score at rest of 3.9 points improved to 0.3 points (P < 0.0001), and that during activity improved from 7.8 points to 0.9 points (P < 0.0001). The mean preoperative JOA elbow score of 29 points was improved to 90 points (P < 0.0001). The mean postoperative DASH score was 10.6 (range 0–50). Absent of T2-weighted high signal focus of the ECRB origin on preoperative magnetic resonance imaging (MRI) (P = 0.02) and receiving public assistance (P = 0.01) were significantly associated with worse DASH scores.ConclusionsArthroscopic release was a satisfactory procedure for chronic lateral epicondylitis. Preoperative MRI of the ECRB origin and socioeconomic factors were significantly associated with postoperative residual symptoms evaluated with the DASH score.

The relationship between the pressure adjacent to the ulnar nerve and the disease causing cubital tunnel syndrome

We investigated the relationship between cubital tunnel pressure in patients with cubital tunnel syndrome with osteoarthritis and those without osteoarthritis. We studied 31 elbows in 29 patients. We divided the patients into two groups: one associated with osteoarthritis and the other not associated with osteoarthritis. In the latter group, there was ulnar nerve subluxation in 10 elbows and cubitus valgus in 3. Cubital tunnel pressure was measured intraoperatively with a fiberoptic microtransducer. The extraneural pressure with the elbow flexed was significantly increased in patients with osteoarthritis and those without osteoarthritis. The pressure within the cubital tunnel in osteoarthritic elbows was significantly higher than that in those without osteoarthritis. Moreover, the pressure of osteoarthritic elbows significantly increased from proximally to distally within the cubital tunnel, whereas the pressure in elbows without osteoarthritis was high only proximally. Thus, cubital tunnel pressure could be a more important causative factor for cubital tunnel syndrome in the elbows with osteoarthritis than in those without osteoarthritis.

Clinical outcomes of corrective osteotomy for distal radial malunion: a review of opening and closing-wedge techniques.

BACKGROUND Radial corrective osteotomy is an established but challenging treatment for distal radial malunion. There is ongoing discussion over whether an opening or closing-wedge osteotomy should be employed. The purpose of the present study was to retrospectively compare the clinical and radiographic results of conventional opening-wedge osteotomy with those of our closing-wedge technique. METHODS We retrospectively evaluated forty-two patients with extra-articular distal radial malunion who were managed with corrective osteotomy and were followed for a minimum of one year. Twenty-two patients were managed with radial opening-wedge osteotomy and interpositional bone graft or bone-graft substitute, and twenty were managed with simultaneous radial closing-wedge and ulnar shortening osteotomy without bone graft. The selection of the surgical procedure was determined by the surgeon. Each patient was evaluated on the basis of objective radiographic measurements and functional outcomes as determined on the basis of clinical examination, including range of wrist motion, grip strength, pain-rating score, Mayo wrist score, and Disabilities of the Arm, Shoulder and Hand (DASH) score. RESULTS The mean duration of follow-up was thirty-six months (range, twelve to 101 months) for the opening-wedge cohort and twenty-eight months (range, twelve to eighty-seven months) for the closing-wedge cohort. The two techniques were comparable in terms of complications. Postoperative volar tilt and ulnar variance improved significantly compared with the preoperative status in each cohort (p < 0.05). Restoration of ulnar variance to within defined criteria (-2.5 to 0.5 mm) was significantly more frequent in the closing-wedge cohort than in the opening-wedge cohort (p < 0.001). The postoperative mean extension-flexion arc of the wrist (p < 0.001) and Mayo wrist score (p = 0.008) were significantly better in the closing-wedge cohort. Differences between the two cohorts in terms of the pronation-supination arc, grip strength, pain-rating score, and DASH scores were not significant. CONCLUSIONS The closing-wedge osteotomy technique is an effective reconstructive procedure for the treatment of extra-articular distal radial malunion. It is significantly better than the opening-wedge osteotomy technique in terms of the restoration of ulnar variance, the extension-flexion arc of wrist motion, and the Mayo wrist score.

Transforming growth factor-β (TGF-β) expression is increased in the subsynovial connective tissues of patients with idiopathic carpal tunnel syndrome.

Non‐inflammatory fibrosis of the subsynovial connective tissue (SSCT) is a hallmark of carpal tunnel syndrome (CTS). The etiology of this finding and its relationship to the development of CTS remain poorly understood. Recent studies have found that transforming growth factor‐β (TGF‐β) plays a central role in fibrosis. The purpose of this study was to investigate the expression of TGF‐β and connective tissue growth factor (CTGF), a downstream mediator of TGF‐β, in the pathogenesis of CTS. We compared SSCT specimens from 26 idiopathic CTS patients with specimens from 10 human cadaver controls with no previous diagnosis of CTS. Immunohistochemistry was performed to determine levels TGF‐β1, CTGF, collagen 1(Col1) and collagen 3 (Col3) expression. TGF‐β1 (p < 0.01), CTGF (p < 0.01), and Col3 (p < 0.01) were increased in SSCT of CTS patients compared with control tissue. In addition, a strong positive correlation was found between TGF‐β1 and CTGF, (R2 = 0.80, p < 0.01) and a moderate positive correlation between Col3 and TGF‐β1 (R2 = 0.49, p < 0.01). These finding suggest that there is an increased expression of TGF‐β and CTGF, a TGF‐β regulated protein, and that this TGF‐β activation may be responsible for SSCT fibrosis in CTS patients.

Skeletal muscle and bone marrow derived stromal cells: A comparison of tenocyte differentiation capabilities

This study investigated the comparative ability of bone marrow and skeletal muscle derived stromal cells (BMSCs and SMSCs) to express a tenocyte phenotype, and whether this expression could be augmented by growth and differentiation factor‐5 (GDF‐5). Tissue harvest was performed on the hind limbs of seven dogs. Stromal cells were isolated via serial expansion in culture. After four passages, tenogenesis was induced using either ascorbic acid alone or in conjunction with GDF‐5. CD44, tenomodulin, collagen I, and collagen III expression levels were compared for each culture condition at 7 and 14 days following induction. Immunohistochemistry (IHC) was performed to evaluate cell morphology and production of tenomodulin and collagen I. SMSCs and BMSCs were successfully isolated in culture. Following tenocytic induction, SMSCs demonstrated an increased mean relative expression of tenomodulin, collagen I, and collagen III at 14 days. BMSCs only showed increased mean relative expression of collagen I, and collagen III at 14 days. IHC revealed positive staining for tenomodulin and collagen I at 14 days for both cell types. The morphology of skeletal muscle derived stromal cells at 14 days had an organized appearance in contrast to the haphazard arrangement of the bone marrow derived cells. GDF‐5 did not affect gene expression, cell staining, or cell morphology significantly. Stromal cells from either bone marrow or skeletal muscle can be induced to increase expression of matrix genes; however, based on expression of tenomodulin and cell culture morphology SMSCs may be a more ideal candidate for tenocytic differentiation.

A Comparative Study of the Effects of Growth and Differentiation Factor 5 on Muscle-Derived Stem Cells and Bone Marrow Stromal Cells in an In Vitro Tendon Healing Model

PURPOSE To investigate the ability of muscle-derived stem cells (MDSCs) supplemented with growth and differentiation factor-5 (GDF-5) to improve tendon healing compared with bone marrow stromal cells (BMSCs) in an in vitro tendon culture model. METHODS Eighty canine flexor digitorum profundus tendons were assigned into 5 groups: repaired tendon (1) without gel patch interposition (no cell group), (2) with BMSC-seeded gel patch interposition (BMSC group), (3) with MDSC-seeded gel patch interposition (MDSC group), (4) with GDF-5-treated BMSC-seeded gel patch interposition (BMSC+GDF-5 group), and (5) with GDF-5-treated MDSC-seeded gel patch interposition (MDSC+GDF-5 group). After culturing for 2 or 4 weeks, the failure strength of the healing tendons was measured. The tendons were also evaluated histologically. RESULTS The failure strength of the repaired tendon in the MDSC+GDF-5 group was significantly higher than that of the non-cell and BMSC groups. The stiffness of the repaired tendons in the MDSC+GDF-5 group was significantly higher than that of the non-cell group. Histologically, the implanted cells became incorporated into the original tendon in all 4 cell-seeded groups. CONCLUSIONS Interposition of a multilayered GDF-5 and MDSC-seeded collagen gel patch at the repair site enhanced tendon healing compared with a similar patch using BMSC. However, this increase in vitro was relatively small. In the clinical setting, differences between MDSC and BMSC may not be substantially different, and it remains to be shown that such methods might enhance the results of an uncomplicated tendon repair clinically. CLINICAL RELEVANCE Muscle-derived stem cell implantation and administration of GDF-5 may improve the outcome of tendon repair.

Changes in urinary NTX levels in patients with primary osteoporosis undergoing long-term bisphosphonate treatment

BackgroundBisphosphonates, antiresorptive drugs, are widely used to treat osteoporosis patients. However, recent reports indicated that several osteoporosis patients who underwent long-term bisphosphonate therapy subsequently developed severe suppression of bone turnover. We investigated whether urinary crosslinked N-telopeptide of type I collagen (NTX), a bone resorption marker, in osteoporosis patients was highly suppressed during long-term treatment with alendronate or risedronate.MethodsWe investigated 87 primary osteoporosis outpatients who were treated with alendronate or risedronate for more than 2 years. All patients were women, with an average age of 72.6 years. Altogether, 49 patients were treated with alendronate and 38 with risedronate, and the average administration period was 3.5 years. We defined high suppression as NTX being reduced <9.3 nmol bone collagen equivalent/mmol·Cr and a 35% decrease from baseline.ResultsIn total, 11 of 87 patients (12.6%) had high NTX suppression based on the above criteria. The incidences of high suppression of NTX at 1,2,3,and 4 years after starting the treatment were 0%, 1.1%, 11.9%, and 4.7%, respectively. The average age, bone mineral density, and NTX values at baseline and the administration period were not associated with high suppression of NTX during alendronate or risedronate treatment. Regarding suppression of NTX during long-term treatment, there was no significant difference between alendronate and risedronate.ConclusionsThe results suggested that long-term treatment with bisphosphonates necessitates careful follow-up of the patients.

The Effect of Surface Modification on Gliding Ability of Decellularized Flexor Tendon in a Canine Model In Vitro

PURPOSE To investigate the gliding ability and mechanical properties of decellularized intrasynovial tendons with and without surface modification designed to reduce gliding resistance. METHODS We randomly assigned 33 canine flexor digitorum profundus tendons to 1 of 3 groups: untreated fresh tendons, to serve as a control; tendons decellularized with trypsin and Triton X-100; and tendons decellularized as in group 2 with surface modification using carbodiimide-derivatized hyaluronic acid and gelatin (cd-HA-gelatin). Tendons were subjected to cyclic friction testing for 1,000 cycles with subsequent tensile stiffness testing. We qualitatively evaluated the surface roughness after 1,000 cycles using scanning electron microscopy. RESULTS The gliding resistance of the decellularized group was significantly higher than that of both the control and cd-HA-gelatin tendons (0.20, 0.09, and 0.11 N after the first cycle; and 0.41, 0.09, and 0.14 N after 1,000 cycles, respectively). Gliding resistance between the control and cd-HA-gelatin groups was not significantly different. The Young modulus was not significantly different between groups. The surfaces of the control and cd-HA-gelatin-treated tendons appeared smooth after 1,000 cycles, whereas those of the decellularized tendons appeared roughened under scanning electron microscopy observation. CONCLUSIONS Decellularization with trypsin and Triton X-100 did not change tendon stiffness. However, although this treatment was effective in removing cells, it adversely altered the tendon surface in both appearance and gliding resistance. Surface modification with cd-HA-gelatin improved the tendon surface smoothness and significantly decreased the gliding resistance. CLINICAL RELEVANCE The combination of decellularization and surface modification may improve the function of tendon allografts when used clinically.

Nonunion of the Ulnar Styloid Associated With Distal Radius Malunion

PURPOSE Malunion is a complication of distal radius fractures and may be associated with a nonunion of the ulnar styloid. We tested the null hypothesis that there is no difference in outcome between patients without ulnar styloid fracture and those with the ulnar styloid nonunion after corrective radial osteotomy for distal radius malunion. METHODS A total of 19 patients with dorsally angulated distal radius malunion who had simultaneous radial closing-wedge and ulnar shortening osteotomies were included. There were 16 women and 3 men with a mean age of 63 years. All patients were followed up for a minimum of 1 year. During surgery, the accompanying ulnar styloid nonunion was not internally fixed in any patient. Eight patients had no ulnar styloid fracture, and 11 had a nonunion of the ulnar styloid. Each group of patients was evaluated on the basis of objective radiographic measurements and functional outcomes as determined on the basis of clinical examination, including wrist motion, grip strength, pain-rating score, Mayo wrist score, and Disabilities of the Arm, Shoulder, and Hand score. RESULTS There were no differences in the demographic and preoperative radiographic measurements between the nonfracture and nonunion groups. Postoperative radiographic measurements and functional outcomes improved significantly compared with the preoperative status in both groups. There were no significant differences in postoperative radiographic measurements, motion, strength, pain scores, Mayo scores, or Disabilities of the Arm, Shoulder, and Hand scores between the 2 groups. Four of the 11 ulnar styloid nonunions were healed within 1 to 12 months after corrective radial osteotomy. CONCLUSIONS An accompanying ulnar styloid nonunion in patients with distal radius malunion has no apparent adverse effect on outcome or function after corrective radial osteotomy. An accompanying nonunion of the ulnar styloid can heal following corrective radial osteotomy.

Effects of lubricant and autologous bone marrow stromal cell augmentation on immobilized flexor tendon repairs.

The purpose of the study was to test a novel treatment that carbodiimide‐derivatized‐hyaluronic acid‐lubricin (cd‐HA‐lubricin) combined cell‐based therapy in an immobilized flexor tendon repair in a canine model. Seventy‐eight flexor tendons from 39 dogs were transected. One tendon was treated with cd‐HA‐lubricin plus an interpositional graft of 8 × 105 BMSCs and GDF‐5. The other tendon was repaired without treatment. After 21 day of immobilization, 19 dogs were sacrificed; the remaining 20 dogs underwent a 21‐day rehabilitation protocol before euthanasia. The work of flexion, tendon gliding resistance, and adhesion score in treated tendons were significantly less than the untreated tendons (p < 0.05). The failure strength of the untreated tendons was higher than the treated tendons at 21 and 42 days (p < 0.05). However, there is no significant difference in stiffness between two groups at day 42. Histologic analysis of treated tendons showed a smooth surface and viable transplanted cells 42 days after the repair, whereas untreated tendons showed severe adhesion formation around the repair site. The combination of lubricant and cell treatment resulted in significantly improved digit function, reduced adhesion formation. This novel treatment can address the unmet needs of patients who are unable to commence an early mobilization protocol after flexor tendon repair.