Biomedical subjects

Akio Minami

Publications and source records attributed to Akio Minami.

At least 91 records · Page 5Linked to original sources

PubMed2003

Timing of administration of transforming growth factor-beta and epidermal growth factor influences the effect on material properties of the in situ frozen-thawed anterior cruciate ligament.

One of the future goals in ligament reconstruction is to prevent graft deterioration after transplantation. The aim of this study is to clarify whether an administration of TGF-beta1 and EGF significantly affect biomechanical properties of the in situ frozen-thawed anterior cruciate ligament (ACL), an ACL autograft model, and to elucidate whether the timing of this administration may influence its effect. Rabbits were randomly divided into 4 groups after the freeze-thaw treatment with liquid nitrogen was applied to the right knee. In 2 groups, 4-ng TGF-beta1 and 100-ng EGF mixed with 0.2-ml fibrin sealant were applied around the ACL at 3 and 6 weeks after the treatment, respectively. In the remaining two groups, only 0.2-ml fibrin sealant was applied around the ACL at 3 and 6 weeks, respectively. In each group, all animals were sacrificed at 12 weeks after the freeze-thaw treatment. These growth factors applied at 3 weeks significantly inhibited not only the increase of water content and the cross-sectional area of the ACL but also reduction of the tensile strength and the tangent modulus of the ACL (p<0.0001), which were induced by the freeze-thaw treatment. However, the application at 6 weeks did not significantly affect the changes of these parameters after the treatment. This study demonstrated that the timing of administration of TGF-beta and EGF after the freeze-thaw treatment significantly influences its effect on the biomechanical properties of the frozen-thawed ACL.

Animals↗

PubMed2003

Effects of stress deprivation on mechanical properties of the in situ frozen-thawed semitendinosus tendon in rabbits.

OBJECTIVE: To clarify the effect of complete stress deprivation on the mechanical properties of the in situ frozen-thawed semitendinosus tendon, an idealized autograft model. DESIGN: Ninety-six rabbits were divided into three groups. In the frozen group (n=36), we applied the freeze-thaw treatment to the semitendinosus tendon to necrotize fibroblasts in the tendon. In the frozen and stress-shielded group (n=30), after we applied the same freeze-thaw treatment to the tendon, we completely released the tendon from stress. In the sham group (n=30), a sham operation was applied. In each group, 6 rabbits were sacrificed at 0 (only in the frozen group), 1, 2, 3, 6 and 12 weeks after surgery. BACKGROUND: Previous studies have not clarified remodeling of the semitendinosus autograft in ligament reconstruction or its idealized model. METHODS: The tendon was frozen with liquid nitrogen. The tendon was released from stress with the originally developed technique using a polyester tape. In each period, 5 out of the 6 rabbits were evaluated with tensile testing, and the remaining rabbit was histologically observed. RESULTS: Complete stress shielding significantly increased the cross-sectional area of the frozen-thawed tendon at 1 and 2 weeks, while it significantly inhibited the increase of the area due to the freeze-thaw treatment at 3 and 6 weeks. Complete stress shielding significantly reduced material properties of the frozen-thawed tendon after 2 weeks. CONCLUSIONS: The frozen-thawed semitendinosus tendon has unique remodeling characteristics under a stress-shielded condition, which were not the same as those of the frozen-thawed patellar tendon. RELEVANCE: Remodeling of the semitendinosus tendon autograft under stress-shielded conditions may be different from that of the patellar tendon autograft.

Animals↗

PubMed2003

Biomechanical evaluation of a newly devised model for the elongation-type anterior cruciate ligament injury with partial laceration and permanent elongation.

OBJECTIVE: To biomechanically evaluate a newly devised model for the elongation-type anterior cruciate ligament injury with partial laceration and permanent elongation. DESIGN: Thirty-six rabbits were randomly divided into 4 groups of 9 animals each, after a quantitative injury was given to the right anterior cruciate ligament. The 4 groups were sacrificed at 0, 6, 12, and 24 weeks after surgery, respectively. Biomechanical and histological evaluations were performed at each period. BACKGROUND: No adequate animal models have been established for the elongation-type anterior cruciate ligament injury in which the mid-substance is permanently elongated with partial laceration. METHODS: The anteromedial and posterolateral half of the anterior cruciate ligament was transected at the proximal and distal one-third levels, respectively. Then, the anterior cruciate ligament was stretched by applying an anterior drawer force to the tibia at 90 degrees of knee flexion. RESULTS: The treatment significantly increased the anterior translation of the knee into approximately 150-250% at each period after surgery. The maximum load and the stiffness of the femur-anterior cruciate ligament-tibia complex significantly decreased to 30% or less immediately after surgery, and then gradually increased to 50% at 12 weeks. CONCLUSIONS: In this model, this quantitative treatment created serious injuries with partial laceration and permanent elongation in the anterior cruciate ligament to similar degrees. Also, incomplete tissue healing occurred in the anterior cruciate ligament to similar degrees after the treatment. RELEVANCE: This model will be useful to study new therapeutic methods for the elongation-type anterior cruciate ligament injury.

Animals↗

PubMed2003

Stress distribution patterns at the coracoacromial arch in rotator cuff tear measured by computed tomography osteoabsorptiometry.

When a rotator cuff tear occurs, forces compressing the humeral head toward the glenoid are disturbed, and the kinematics of the glenohumeral joint change. Therefore, stress distributions at the coracoacromial arch in cuff tear shoulders should differ from those in normal shoulders. To investigate this hypothesis, we studied stress distribution patterns at the coracoacromial arch in normal and cuff tear shoulders using a computed tomography (CT) osteoabsorptiometry method, in which bone density correlates directly with long-term physiologic loading. Eight normal subjects and 11 patients with cuff tear were examined. The stress distributions at the undersurface of the acromion and the posterolateral surface of the coracoid process differed markedly between normal and cuff tear shoulders. In cuff tear shoulders, a high-density area was located at the anterior or the anterolateral part of the undersurface of the acromion, while it was located at the posterior part in all but one normal shoulder. Additionally, a high-density area was located at the superior or the lateral part of the coracoid process in most of the cuff tear shoulders; on the other hand, it was located at the base in all but one normal shoulder. We believe that the differences in stress distribution patterns are due to impingement at the coracoacromial arch in cuff tear shoulders. CT osteoabsorptiometry can provide useful information in performing coracoacromial arch decompression for cuff tear shoulders.

Adult↗

PubMed2003

Implantation sites and fiber diameters affect the rate of degradation in absorbable polydioxanone fibers.

PURPOSE: The purpose of this study is to test the question of whether implantation sites and fiber diameters affect the rate of degradation in absorbable polydioxanone fibers. TYPE OF STUDY: Randomized trial. METHODS: Forty-eight mature rabbits were used. In the first study, using 24 rabbits, a 0.3-mm diameter polydioxanone fiber was implanted into the subcutaneous, intra-articular, and intramedullary sites. Six rabbits each were killed at 1, 2, 3, and 6 weeks after surgery. In the second study, the remaining 24 rabbits were divided into 2 groups of 12 animals each. In group I, a 0.3-mm diameter fiber was implanted into the intramedullary and subcutaneous sites. In group II, a 0.6-mm diameter fiber was implanted in the same manner. In each group, 6 rabbits were killed at 3 and 6 weeks. In each study, all fiber specimens underwent tensile testing to determine the material properties. We defined the percentage of the maximum load of each fiber specimen compared with the normal control value as the I/N ratio. RESULTS: In the first study, the maximum load and the stiffness of the fibers implanted into the intramedullary site were significantly lower than those of the fibers implanted into the other 2 sites at each period (P <.0001). In the second study, the I/N ratio of group I was significantly less than that of group II at each implanted site (P <.0001). CONCLUSIONS: Polydioxanone fiber implanted into the intramedullary site deteriorates more rapidly than that implanted into the subcutaneous and the intra-articular sites. Thin fibers deteriorate more rapidly than thick fibers. Therefore, the degradation of absorbable synthetic fibers intended for use in ligament reconstruction should be evaluated not only in the subcutaneous site but also in the intramedullary site using various diameter fibers.

Absorbable Implants↗

PubMed2003

Acute posterior interosseous nerve palsy caused by septic arthritis of the elbow: a case report.

A rare case of acute posterior interosseous nerve palsy caused by septic elbow arthritis is reported. The nerve was compressed beneath the arcade of Frohse by hypertrophied synovium and joint fluid at the anterior aspect of the radial neck. Decompression of the nerve, synovectomy, and irrigation of the elbow joint were done. effective. Six months after the surgery the nerve palsy had recovered completely. Two years after surgery there was no recurrence of the infection or nerve palsy.

Adult↗

PubMed2003

Acetabular components without bulk bone graft in revision surgery: A 5- to 13-year follow-up study.

Eighty-three consecutive revisions in 74 patients using a porous-coated acetabular component without bulk bone graft were followed up for an average of 9.3 years (range, 5-13 years). A large-diameter cup was implanted in hips with adequate osseous support, and a high hip center technique using a standard- or smaller-diameter cup was selected in hips without sufficient bone stock. Acetabular bone deficiency was segmental in 18 hips, cavitary in 30, and combined segmental and cavitary in 35. Four (5%) cups were revised again; 1 for infection, 1 for dislodgement of the polyethylene liner from the metal shell, and 2 for recurrent dislocation. No acetabular components were categorized as definitely loose at final follow-up. The current satisfactory results encourage the use of this simple technique.

Acetabulum↗

PubMed2003

Telescoping vascularized fibular graft: a new method.

The authors describe a case of congenital pseudarthrosis of the tibia treated with a telescoping vascularized fibular graft. The advantages of this new method are that bone union and leg-length discrepancy may be corrected simultaneously.

Bone Transplantation↗

PubMed2003

Ingestion of difructose anhydride III and voluntary running exercise independently increase femoral and tibial bone mineral density and bone strength with increasing calcium absorption in rats.

Difructose anhydride III (DFAIII), a nondigestible disaccharide, promotes intestinal calcium absorption. Exercise-induced mechanical stimuli are essential for bone growth. In the present study, we examined the effects of consuming DFAIII and voluntary running exercise on calcium absorption and bone characteristics using male Sprague-Dawley rats (4 wk old). The study was designed in a 2 x 2 factorial arrangement with two conditions (sedentary or exercised) and two diets [AIN-93G diet with or without DFAIII (30 g/kg diet)]. Both consuming DFAIII and running exercise increased net calcium absorption, and the effects of DFAIII and exercise were additive. Both consuming DFAIII and exercise also increased femoral variables such as calcium content and total bone mineral density (BMD); however, only consuming DFAIII increased bone strength in the femur. Conversely, running exercise augmented tibial calcium content, total BMD and bone strength, but consuming DFAIII did not. We conclude that consuming DFAIII and running exercise additively enhance calcium absorption and differentially stimulate femoral and tibial BMD and mechanical properties in rats.

Absorption↗

PubMed2003

Predictors of clinical results of radial osteotomies for Kienböck's disease.

The factors affecting the clinical results after radial osteotomies for Kienböck's disease are unknown. In the current study, we reviewed the data of 41 patients treated with radial osteotomies for Kienböck's disease and analyzed which preoperative factors significantly affected the clinical results of these procedures. Lateral closing wedge osteotomies of the radius were done for 22 patients (six patients with Lichtman Stage II disease, three patients with Lichtman Stage IIIA disease, 12 patients with Lichtman Stage IIIB disease, and one patient with Lichtman Stage IV disease) with zero or positive ulnar variance, and radial shortenings were done for 19 patients (four patients with Stage II disease, two patients with Stage IIIA disease, 12 patients with Stage IIIB disease, and one patient with Stage IV disease) with negative ulnar variance. The mean age of the patients at surgery was 36 years and the average followup was 38 months. To statistically assess the prognostic factors, multiple regression analysis focused on the postoperative clinical score as a dependent variable and preoperative patient data as independent variables. In the current analysis, patient age was the preoperative factor most clearly predictive of clinical results after radial osteotomies for Kienböck's disease. We think that the lower effectiveness of radial osteotomies must be considered in doing these procedures for elderly patients.

Adolescent↗

PubMed2003

Treatment of scapholunate dissociation: ligamentous repair associated with modified dorsal capsulodesis.

We previously reported that our repair and/or reconstruction of the scapholunate interosseous ligament reduced the scapholunate dissociation and improved the clinical results. Re-evaluation of these patients after three years revealed that malrotation of the scaphoid advanced significantly although the clinical results declined only slightly. To prevent progression of scaphoid malrotation, a modified dorsal capsulodesis was subsequently added to the ligamentous repair of scapholunate dissociation. The records of 17 patients were available for this study. The time lapse from injury to surgical treatment ranged from four days to one year and six months. All but three patients were operated less than two months after the injury. All patients were followed for more than one year, with an average of 49 months. Clinical results were expressed by a modification of the point score method of Green and O'Brien. Scapholunate angles were measured on lateral X-ray films with the wrist in neutral position. Overall clinical results averaged 83 points (range: 25-100). The scapholunate angles averaged 49 degrees (range: 45-60). In the three patients, in whom the operation was performed more than 11 months after the injury, the clinical results averaged 38 points and scapholunate angles averaged 54 degrees, respectively. These clinical and X-ray results suggest that early repair of the scapholunate interosseous ligament along with a modified dorsal capsulodesis is a useful procedure in the treatment of scapholunate dissociation.

Adult↗

PubMed2003

Intermediate-term results after hybrid total hip arthroplasty for the treatment of dysplastic hips.

BACKGROUND: In recent studies, good intermediate-term results have been reported after primary hybrid total hip arthroplasty (a cementless acetabular component with a cemented femoral stem) for the treatment of primary osteoarthritis. However, few studies have described the results of this technique in patients with developmental dysplasia of the hip. METHODS: One hundred primary hybrid total hip replacements were performed in ninety patients to treat degenerative arthritis of the hip secondary to developmental dysplasia. Seventy-one patients (eighty-one hips) were available for clinical and radiographic evaluation. The average duration of follow-up was 10.6 years. There were ten men and sixty-one women. Seventy hips were classified as type 1 (dysplasia); seven, as type 2 (low dislocation); and four, as type 3 (high dislocation), according to the classification system of Hartofilakidis et al. RESULTS: At the time of the final follow-up, the average Harris hip score was 86 points. Structural autograft was used in fifteen hips to supplement acetabular coverage. Within five years postoperatively, the acetabular component in six of the fifteen hips had an average of 4.5 mm of vertical migration and an average increase in vertical rotation of 3 degrees, but the position appeared to stabilize thereafter. Revisions were performed in two hips because of recurrent dislocation. No acetabular or femoral component was revised because of aseptic loosening. Osteolysis was identified around two acetabular components and two femoral components. The average rate of polyethylene wear was 0.09 mm per year. CONCLUSIONS: Hybrid total hip arthroplasty for the treatment of symptomatic degenerative arthritis secondary to developmental dysplasia provides favorable results at intermediate-term follow-up. With lower grades of dysplasia, the majority of patients can be treated effectively without a structural bone graft by placement of the cementless acetabular component at a medial or high position.

Adult↗

PubMed2003

Diagnostic accuracy of magnetic resonance imaging for detecting posterior ligamentous complex injury associated with thoracic and lumbar fractures.

OBJECT: The posterior ligamentous complex (PLC) in the thoracic and lumbar spine is one of the region's important stabilizers. The precise diagnosis of PLC injury is required to evaluate the instability of the injured spine; however, the accuracy of magnetic resonance (MR) imaging for diagnosing PLC injury has remained unclear. In this study, the authors compared preoperative MR imaging findings with direct intraoperative observation of PLC injury, clarifying the former's diagnostic accuracy regarding detection of PLC injury associated with the thoracic and lumbar fractures. METHODS: Data obtained in 35 patients who sustained thoracic or lumbar injuries were reviewed. There were 17 burst fractures, six flexion-distraction injuries, and 12 fracture dislocations. Each patient underwent MR imaging examination within 3 weeks of injury. Three radiologists independently evaluated sagittal MR images in a blinded fashion. The PLC-related information was retrospectively collected from each operative record. The diagnostic accuracy of MR imaging was analyzed by comparing imaging-documented intraoperative findings. The PLC injuries were detected in 23 patients (65.7%) by direct observation during posterior spinal procedures. The diagnostic accuracy of MR imaging in detecting injury of the supraspinous ligament (SSL) and interspinous ligament (ISL) was 90.5 and 94.3%, respectively. The specificity of T1-weighted MR imaging alone for depicting the SSL was significantly greater than T2-weighted imaging alone (p < 0.05). The overall mean kappa coefficient for MR imaging findings of PLC injury was 0.803, which indicated excellent interobserver reliability; that for ISL (0.915) was significantly greater than that for SSL (0.69) (p < 0.05). CONCLUSIONS: This study clarified a high diagnostic accuracy and interobserver reliability of MR imaging for PLC injury. The precise diagnosis of PLC injury is essential to determine the mechanical instability of the injured thoracic and lumbar spine, especially in differentiating unstable (three-column) burst fractures from the relatively stable (two-column) type. The authors conclude that MR imaging is a powerful diagnostic tool to evaluate PLC injury associated with thoracic and lumbar fractures.

Humans↗

PubMed2003

In vitro biomechanical effects of reconstruction on adjacent motion segment: comparison of aligned/kyphotic posterolateral fusion with aligned posterior lumbar interbody fusion/posterolateral fusion.

OBJECT: Posterior lumbar interbody fusion (PLIF) was developed to overcome the limitations of posterolateral fusion in correcting spinal deformity and maintaining lumbar lordosis. In this study the authors compare the biomechanical effects of three different posterior reconstructions on the adjacent motion segment. METHODS: Ten calf spinal (L2-S1) specimens underwent nondestructive flexion-extension testing (+/- 6 Nm). The specimens were destabilized at the L5-S1 levels after intact testing. This was followed by pedicle screw fixation with and without interbody cages as follows: 1) with straight rods ("aligned" posterolateral fusion); 2) with kyphotically prebent rods ("kyphotic" posterolateral fusion); and 3) with interbody cages combined with straight rods ("aligned" PLIF/posterolateral fusion). The range of motion (ROM) of the operative segments, the intradiscal pressure (IDP), and longitudinal lamina strain in the superior adjacent segment (L4-5) were analyzed. The ROM associated with aligned PLIF/posterolateral fusion-treated specimens was significantly less than both the aligned and kyphotic posterolateral fusion-treated procedures in both flexion and extension loading (p < 0.05). The aligned PLIF/posterolateral fusion was associated with greater IDP and the lamina strain compared with the aligned and kyphotic posterolateral fusion groups in flexion loading. Under extension loading, greater IDP and lamina strain were present in the kyphotic posterolateral fusion group than in the aligned posterolateral fusion group. The highest IDP and lamina strain were shown in the aligned PLIF/posterolateral fusion group. CONCLUSIONS: Compared with kyphotic posterolateral fusion, PLIF may lead to even higher load at the superior adjacent level because of the increased stiffness of the fixed segments even if local kyphosis is corrected by PLIF.

Animals↗

PubMed2003

Improved accuracy of computer-assisted cervical pedicle screw insertion.

OBJECT: The authors introduce a unique computer-assisted cervical pedicle screw (CPS) insertion technique used in conjunction with specially modified original pedicle screw insertion instruments. The accuracy of screw placement as well as surgery-related outcome and complication rates were compared between two groups of patients: those in whom a computer-assisted and those in whom a conventional manual insertion technique was used. METHODS: The screw insertion guiding system consisted of a modified awl, probe, tap and a screwdriver specially designed for a computer-assisted CPS insertion. Using this system, real-time instrument/screw tip information was three dimensionally identified in each step of screw insertion. Seventeen patients underwent CPS fixation in which a computer-assisted surgical navigation system was used. The cervical disorders consisted of spondylotic myelopathy with segmental instability or kyphosis, metastatic spinal tumor, rheumatoid spine, and postlaminectomy kyphosis. The rate of pedicle wall perforation was significantly lower in the computer-assisted group than that in the other group (1.2 and 6.7%, respectively; p < 0.05). The screw trajectory in the horizontal plane was significantly closer to the anatomical pedicle axis in the computer-assisted group compared with the manual insertion group (p < 0.05). This factor significantly reduced the incidence of screw perforation laterally. Complications such as neural damage or vascular injury were not demonstrated in the computer-assisted group (compared with 2% in the manual insertion treatment group). The overall surgery-related outcome was satisfactory. CONCLUSIONS: In contrast to the previously reported computer-assisted technique, our CPS insertion technique provides real-time three-dimensional instrument/screw tip information. This serves as a powerful tool for safe and accurate pedicle screw placement in the cervical spine.

Adolescent↗

PubMed2002

Complications related to hydroxyapatite vertebral spacer in anterior cervical spine surgery.

STUDY DESIGN: This is a report of complications related to the hydroxyapatite vertebral spacer used for anterior cervical reconstructive surgery. Compression of the spinal cord by broken fragments of hydroxyapatite spacer as well as its surrounding radiolucent clear zone were observed in seven patients. OBJECTIVES: To report complications related to the use of hydroxyapatite vertebral spacer for anterior cervical reconstructive surgery and to discuss how to prevent these complications. SUMMARY OF BACKGROUND DATA: Despite previous articles reporting the clinical applications of hydroxyapatite vertebral spacer for the cervical spine, clinical reports regarding the long-term results of hydroxyapatite spacer for anterior cervical surgery and its complications have been limited. METHODS: The authors reviewed patients who underwent anterior reconstructive surgery using the hydroxyapatite spacer at other hospitals and had postoperative complications related to hydroxyapatite spacer. RESULTS: Seven patients previously treated by anterior cervical spine surgery using the hydroxyapatite vertebral spacer were referred to the authors because of unsatisfactory surgical outcomes. All the patients had a radiolucent clear zone around the spacer and experienced severe neck pain. Four had fracture of the hydroxyapatite spacer, and two had compression of the spinal cord by retropulsed fragments of broken hydroxyapatite spacers. CONCLUSIONS: Although hydroxyapatite has been used in many medical fields because of its bioactive characteristics, its mechanical properties should be improved to lessen the risks of breakage and subsequent spinal cord compression. Gentle insertion maneuvers are also important to avoid the production of cracks inside the spacer.

Aged↗

PubMed2002

Feasibility of immunosuppression in composite tissue allografts by systemic administration of CTLA4Ig.

BACKGROUND: Although recent experimental studies have demonstrated CTLA4Ig to be a potent immunosuppressant in vascularized solid organ allografts, little attention has been given to the effect of this soluble recombinant fusion protein on immunosuppression in composite tissue allografts (CTAs). Using a rat hind limb allograft model, we examined the efficacy of CTLA4Ig against the allograft rejection of composite tissue. METHODS: The hind limbs of ACI rats (RT1a) were heterotopically transplanted to Lewis rats (RT11). Controls received no immunotherapy. Experimental recipients were treated with a single i.p. injection of either human immunoglobulin (Ig)G (0.5 mg/body) or CTLA4Ig (0.5 mg/body) according to different time schedules. Graft survival time and histopathological changes for each experimental group were evaluated and statistically compared. RESULTS: Graft survival times were prolonged significantly in rats treated with CTLA4Ig on day 1 and day 2 after transplantation, compared with survival times of controls. In particular, the most significant prolongation was found in rats treated on day 2. At 7 days after transplantation, moderate-to-severe histological rejection occurred in all tissues in control rats. On the other hand, in rats treated with CTLA4Ig, all tissues showed significantly better preservation. Among these treated rats, the rats treated on day 2 showed excellent histopathological conditions in each tissue. CONCLUSIONS: This study supports the feasibility of using CTLA4Ig for preventing acute rejection in CTA. On the basis of the current results, the administration of CTLA4Ig for CTA is more effective at 24-48 hr after transplantation, after the initial immune response has been allowed to begin.

Abatacept↗

PubMed2002

The correlation between bursoscopic and histologic findings of the acromion undersurface in patients with subacromial impingement syndrome.

PURPOSE: Ideally, decompression of the coracoacromial arch in patients with shoulder impingement syndrome should be done only at the site of impingement. However, it is very difficult to determine the exact site of impingement before acromioplasty. The objectives of this study were to investigate the relationship between findings and the histopathologic changes of the undersurface of the acromion in subacromial impingement syndrome and to evaluate the usefulness of bursoscopy in identifying the site of the impingement. TYPE OF STUDY: Case series. METHODS: We investigated the correlation between subacromial bursoscopic findings and histopathologic changes of the coracoacromial arch in 50 patients with subacromial impingement syndrome. The acromion and the coracoacromial ligaments removed during acromioplasty were fixed in 10% formalin, decalcified, embedded in paraffin, and cut into sections along the direction of the coracoacromial ligament. After staining with toluidine blue, the specimens were evaluated for pathology using an optical microscope. RESULTS: The pathologic changes were classified into 3 types according to the direction of proliferative fibrocartilaginous changes at the enthesis of the acromial insertion of the coracoacromial ligament. The bursoscopic findings were classified into 4 types. Subacromial abnormalities in the bursoscopy findings correlated with histopathologic changes at the undersurface of the acromion. On the other hand, cases with normal findings on the undersurface of the acromion on bursoscopy had hypertrophic changes of fibrocartilage at the insertion of the coracoacromial ligament to the acromion. These results suggest that, with normal findings on the undersurface of the acromion in patients with subacromial impingement syndrome, there is impingement at the coracoacromial ligament. CONCLUSIONS: Bursoscopy is a useful procedure to determine the impingement site in patients with subacromial impingement.

Acromion↗