Kazuma Kikuchi

Prevalence of symptomatic and asymptomatic rotator cuff tears in the general population: From mass-screening in one village.

PURPOSE Rotator cuff tear is the most common shoulder disease in patients with shoulder problems, but its prevalence is not well known. METHODS We performed a health care check-up of locomotive organs in 664 residents (21.3% of the population) in one village. Ultrasonography on bilateral shoulders was performed in all the participants. RESULTS One hundred and forty seven out of 664 subjects (22.1%) had full-thickness rotator cuff tears. The prevalence of tear in each decade was 0% in the 20s to 40s, 10.7% in the 50s, 15.2% in the 60s, 26.5% in the 70s, and 36.6% in the 80s. Symptomatic rotator cuff tears accounted for 34.7% of all tears and asymptomatic tears for 65.3%. The prevalence of asymptomatic rotator cuff tears was one-half of all tears in the 50s, whereas it accounted for two-thirds of those over the age of 60. The prevalence of tear was significantly greater in male than in female in the 50s and 60s, but not in the 70s and 80s. CONCLUSION The prevalence of rotator cuff tear in the general population was 22.1%, which increased with age. Asymptomatic tear was twice as common as symptomatic tear.

Long-term follow-up of cases of rotator cuff tear treated conservatively

BACKGROUND This study clarified the long-term results of conservative treatment of rotator cuff tears. MATERIALS AND METHODS This study focused on 103 shoulders diagnosed with rotator cuff tears by magnetic resonance imaging or arthrography at our institution from 1996 to 1999. Sixty-five shoulders were followed up by telephone survey and 43 of these shoulders were evaluated; 11 shoulders were excluded because the patient had died, 10 shoulders because of severe dementia, and 1 shoulder that had undergone trauma. The mean patient age for these 43 shoulders at the time of diagnosis was 62 years, and the mean follow-up period was 13 years. The pain score (30 points) and the activities-of-daily-life score (10 points) of the Japanese Orthopaedic Association shoulder scoring system were determined. RESULTS The mean pain score was 25.4 points, and the proportion of patients with no pain or with only slight pain was 88%. The mean score for activities of daily life was 9.4 points, and the proportion of patients with no disturbance in daily life was 72%. The patients with fewer than 20 points out of the possible 40 points (30 points for pain score plus 10 points for activities-of-daily-life score) were significantly younger than the other patients. CONCLUSIONS In cases of rotator cuff tears treated conservatively, at 13 years after diagnosis, about 90% of patients had no or only slight pain and about 70% had no disturbance in activities of daily life. However, the younger patients tended to have more significant pain or disorder in daily life more than 10 years after diagnosis.

Scapular inclination and glenohumeral joint stability: a cadaveric study

BackgroundIn shoulders with multidirectional instability, translation of the humeral head on the glenoid is increased in the midrange because of the following three reasons: the increased retroversion, a hypoplastic posteroinferior rim, and decreased scapular abduction during arm elevation. This study aimed to clarify the relationship between glenoid inclination and glenohumeral joint stability.MethodsNine fresh-frozen cadaveric shoulders were tested. With a 50-N compressive load, the translation force was measured in the 3-o’clock, 6-o’clock, 9-o’clock, and 12-o’clock directions by using a tilt of 0°, 5°, 10°, 15°, and 20°. When the glenoid was tilted in one direction, the translation force was measured in the direction of inclination and in the opposite direction. The stability ratio was then calculated.ResultsThe stability ratio in the 3-o’clock direction significantly decreased with a tilt of more than 5° in the 3-o’clock direction. The stability ratio in the 9-o’clock direction significantly decreased with a tilt of more than 15° in the 9-o’clock direction and significantly increased with a tilt of more than 5° in the 3-o’clock direction. The stability ratio in the 6-o’clock direction significantly increased with a tilt of more than 10° in the 6-o’clock direction.ConclusionsThe posterior and inferior stability increased with an anterior tilt of more than 5° and with a superior tilt of 10°, respectively. The anterior and posterior stability decreased with an anterior tilt of 5° and with a posterior tilt of 15°, respectively.

Sarcomere length of torn rotator cuff muscle

BACKGROUND Sarcomere length is one of the factors related to the contractile ability of muscle. There is no report about sarcomere length of torn rotator cuff muscles. The purpose of this study was to clarify sarcomere length of torn rotator cuff muscles. MATERIALS AND METHODS Twenty-eight embalmed cadaver shoulders (14 shoulders with intact rotator cuff and 14 shoulders with full-thickness rotator cuff tears: an isolated tear of the supraspinatus in 3, a combined tear of the supraspinatus and infraspinatus in 4, and a combined tear of the supraspinatus, infraspinatus and subscapularis in 7) were used in this study. Muscle fiber length was measured using a digital caliper. Sarcomere length was measured by laser diffraction method. RESULTS Muscle fiber lengths of the supraspinatus and infraspinatus (33.0 +/- 6.5 mm and 61.5 +/- 14.0 mm, respectively) in the cuff tear group were significantly shorter than those in the intact cuff group (56.9 +/- 10.1 mm and 74.2 +/- 10.0 mm: P < .001 and P = .010). The sarcomere lengths of these muscles were 3.00 +/- 0.44 microm and 3.12 +/- 0.45 microm in the intact cuff group and 2.90 +/- 0.34 microm and 3.01 +/- 0.34 microm in the cuff tear group. The sarcomere lengths showed no significant difference (P = 0.46 and P = .37). CONCLUSION The sarcomere lengths of the supraspinatus and infraspinatus with torn tendons were not significantly different from those with intact tendons, although the muscle fiber lengths were significantly shorter with torn tendons.

Mechanical environment of the supraspinatus tendon: three-dimensional finite element model analysis

BackgroundWe analyzed the mechanical environment of the supraspinatus tendon using a three-dimensional finite element model with the software programs MENTAT and MARC.MethodsThe supraspinatus tendon that attaches to the superior facet was extracted and modeled. The geometric shape of the humeral head was determined from computed tomography images, and the shape of the supraspinatus tendon was determined from magnetic resonance images of the shoulder at 0° of abduction in a healthy 27-year-old man. The distal portion of the humeral head was fixed, and 10 N of tensile force was applied to the proximal end of the tendon. The tensile stress was calculated.ResultsThe tensile stress was 1.8 MPa for the bursal side and 15.0 MPa for the articular side of the anterior portion of the supraspinatus tendon. The intensity was 0 MPa for the bursal side and 4.5 MPa for the articular side of the middle portion of the tendon. The intensity was 0.1 MPa for the bursal side and 5.2 MPa for the posterior edge of the tendon.ConclusionsBased on the three-dimensional finite element method, the maximal tensile stress was observed on the articular side of the anterior edge of the supraspinatus tendon. Our result may explain the frequent occurrence of rotator cuff tears at this site.

Anterior decompression for far-out syndrome below a transitional vertebra: a report of two cases

BACKGROUND CONTEXT Impingement of the L5 nerve between the transverse process of L5 and the ala of sacrum has been described as the far-out syndrome. Posterior decompression is often performed for this pathology. PURPOSE To describe rare cases of far-out syndrome below a transitional vertebra who underwent anterior decompression. STUDY DESIGN/SETTING A case report and a review of the literature. METHODS Review of the hospital medical record, history, physical examination, and imaging studies. RESULTS A 70-year-old woman and a 53-year-old man presented with prolonged and progressive leg pain and/or low back pain. Both of the patients showed muscle weakness and sensory disturbance at L5 level and lumbosacral transitional vertebra on the plain radiography. Magnetic resonance imaging showed huge osteophytes, and there was severe impingement of the L5 nerve at the anterior exit zone of the foramen. Anterior decompression was performed for both cases using a Fraser incision and resulted in successful resolution of the symptom and neurological status. CONCLUSION In the extraforaminal stenosis of the L5 nerve with far-out syndrome below the transitional vertebra, entrapment occurs more anterior of exit zone of the L5 nerve foramen than in the other pathologies; anterior decompression brings in more complete decompression.

Posterior-approach vertebral replacement with rectangular parallelepiped cages (PAVREC) for the treatment of osteoporotic vertebral collapse with neurological deficits.

Study Design: A retrospective clinical study. Objective: To assess the efficacy of a new spinal reconstruction technique (posterior-approach vertebral replacement with rectangular parallelepiped cages: PAVREC) for the treatment of osteoporotic late vertebral collapse with neurological deficits. Summary of Background Data: Poor bone quality and medically complicated situations obfuscate precise treatment for paraplegia caused by osteoporotic vertebral collapse. Recently, posterior-approach corpectomy and replacement with a cylindrical cage have been proposed. However, postoperative cage subsidence and kyphosis progression frequently occurs. Methods: Surgical invasiveness, perioperative complications, and clinical and radiographic outcomes in a total of 19 consecutive patients with osteoporosis (7 men and 12 women; mean age, 75 y) who underwent PAVREC with a mean follow-up period of 45.6 months (range, 16–79 mo) were reviewed. The affected vertebral levels ranged from T12–L4. The mean bone mineral density of the femoral neck was 0.611±0.077 g/cm2 (mean±SD). Results: Mean operative time was 261 minutes (range, 155–326 min). Mean blood loss was 664 mL (range, 197–1595 mL). There were no reported surgical complications. Neurological deficits evaluated with the Frankel grading score improved >1 grade after surgery in all patients. Mean preoperative visual analog scale scores for back or leg pain (7.2; range, 6–9) significantly improved after surgery (1.4; range, 0–2) (P<0.05). Local kyphosis improved from a mean of 24.6 degrees before surgery to a mean of 1.5 degrees after surgery (P<0.05), and it was maintained at a mean of 2.5 degrees at the final follow-up. Although screw loosening, cage subsidence, and subsequent vertebral fracture were seen in several cases, no additional surgeries were needed. Solid bony fusion was confirmed in all cases. Conclusions: PAVREC provided a satisfactory clinical and radiologic outcome without severe complications. This procedure can be a treatment option for osteoporotic vertebral collapse and an alternative to an anterior-approach or single posterior-approach reconstruction with a cylindrical cage.

Anterior Decompression and Shortening Reconstruction with a Titanium Mesh Cage through a Posterior Approach Alone for the Treatment of Lumbar Burst Fractures

Study Design A retrospective study. Purpose To examine the efficacy and safety for a posterior-approach circumferential decompression and shortening reconstruction with a titanium mesh cage for lumbar burst fractures. Overview of Literature Surgical decompression and reconstruction for severely unstable lumbar burst fractures requires an anterior or combined anteroposterior approach. Furthermore, anterior instrumentation for the lower lumbar is restricted through the presence of major vessels. Methods Three patients with an L1 burst fracture, one with an L3 and three with an L4 (5 men, 2 women; mean age, 65.0 years) who underwent circumferential decompression and shortening reconstruction with a titanium mesh cage through a posterior approach alone and a 4-year follow-up were evaluated regarding the clinical and radiological course. Results Mean operative time was 277 minutes. Mean blood loss was 471 ml. In 6 patients, the Frankel score improved more than one grade after surgery, and the remaining patient was at Frankel E both before and after surgery. Mean preoperative visual analogue scale was 7.0, improving to 0.7 postoperatively. Local kyphosis improved from 15.7° before surgery to -11.0° after surgery. In 3 cases regarding the mid to lower lumbar patients, local kyphosis increased more than 10° by 3 months following surgery, due to subsidence of the cages. One patient developed severe tilting and subsidence of the cage, requiring additional surgery. Conclusions The results concerning this small series suggest the feasibility, efficacy, and safety of this treatment for unstable lumbar burst fractures. This technique from a posterior approach alone offers several advantages over traditional anterior or combined anteroposterior approaches.

Three-dimensional ultrasonography of shoulders with rotator cuff tears

BackgroundIt is possible to evaluate the size of rotator cuff tears by ultrasonography (US) or magnetic resonance imaging. However, there are only a few reports on the imaging assessment of the configuration of cuff tears, which could provide important preoperative information that assists performing an optimal anatomical repair. The purpose of this study was to determine quantitatively the reproducibility of three-dimensional US in the assessment of rotator cuff tear configuration.MethodsTen embalmed cadaveric shoulders with rotator cuff tears were examined. After resecting the proximal humerus with the rotator cuff, we put it in water and scanned it using high-resolution US with a three-dimensional linear probe. Actual tear lengths and widths were compared with sonographic measurements (Pearson correlation coefficient). By superimposing the real photographic image on the reconstructed three-dimensional image, we calculated the concordance rate (ratio of the concordance area to the tear area).ResultsThe actual tear length (16.6 ± 7.1 mm; mean ± SD) and width (8.4 ± 4.4 mm) were correlated with the tear length (16.4 ± 7.5 mm) and width (8.2 ± 4.4 mm) measured from reconstructed three-dimensional ultrasonograms (r = 0.998 and 0.994, respectively). The mean concordance rate was 91.4%, indicating that almost exactly the same configuration was reconstructed by US.ConclusionsThree-dimensional US is useful for evaluating the configuration of rotator cuff tears. This is the first report to quantify the similarity between the configuration evaluated by US and the actual configuration. Using this method, we can visualize the configuration of rotator cuff tears preoperatively, facilitating optimal repair design.

Vertebral osteomyelitis and epidural abscess caused by gas gangrene presenting with complete paraplegia: a case report

IntroductionGas gangrene is most often caused by Clostridium perfringens infection. Gas gangrene is a medical emergency that develops suddenly. The mortality rate is higher with trunk involvement than with involvement of the extremities, which carries a better prognosis. With respect to vertebral involvement, there are few reports in the literature. The purpose of this paper is to report a very rare case of vertebral osteomyelitis caused by gas gangrene.Case presentationA 78-year-old Japanese woman with diabetes mellitus was admitted to our hospital with the chief complaints of back pain, dysuria, and complete paralysis of both legs. A computed tomography scan showed soft tissue swelling anterolaterally at intervertebral disc level T11/12 and a gas-containing epidural abscess that compressed her spinal cord. Cultures later grew Clostridium perfringens and Escherichia coli. Hemilaminectomy was done from T10 to T12, and an epidural abscess was removed. She went on to have fusion surgery 6 weeks after the initial operation and subsequently experienced complete pain relief. She was discharged 2 months later, at which time she was able to walk with a cane. Examination 18 months after surgery showed normal gait without a cane.ConclusionsDiscitis caused by gas gangrene infection was successfully treated by immediate debridement and subsequent fusion surgery.