Papers by Kotaro Yamakado
PubMed, 1997
The clamp fixation method using the Tibial Baseplate Clamper in total knee arthroplasty (TKA) is ... more The clamp fixation method using the Tibial Baseplate Clamper in total knee arthroplasty (TKA) is a superior procedure compared to conventional cement fixation methods. A dynamic experimental study and a radiographic study were performed to make sure the efficiency of the clamp fixation method was satisfactory. As a result, this procedure showed the large initial pressure force and a lack of variance in the force applied over time, and also it had a large depth of cement penetration compare to the pusher method. The clamp fixation method will help the surgeon achieve excellent cement fixation in TKAs because it has the many advantages of a gentle, yet strong, constant, and, most importantly, simple approach surgeons can use to reduce operating time while cementing all three prostheses simultaneously.
Modern Rheumatology, Apr 20, 2005
Total knee arthroplasty (TKA) was carried out on both knee joints for spontaneous bony ankylosis ... more Total knee arthroplasty (TKA) was carried out on both knee joints for spontaneous bony ankylosis due to rheumatoid arthritis (RA). Preoperative fixation angles were 40°. First, the peroneal nerve was released prior to TKA. Quadriceps snip was performed to evert the patella laterally. Bilateral TKAs were carried out using a stabilized prosthesis. The results showed full extension to 70° flexion at 3 years after the surgery. Absence of pain, maintenance of stability, and walking ability were achieved, without any significant complication. Total knee arthroplasty following takedown of a spontaneous ankylosed knee is an effective procedure under appropriate knee conditions.
Case reports in orthopedics, 2016
Isolated cuboid fractures are very rare, since they typically occur in combination with midfoot f... more Isolated cuboid fractures are very rare, since they typically occur in combination with midfoot fractures or dislocations. A 61year-old man presented at our hospital with pain and swelling on the outside of his right foot. The lateral column of his right foot was shortened by approximately 6.5 mm on X-ray. CT showed displacement of the joint surface between the cuboid and the fourth metatarsal, with a 3.5 mm depression. An MRI revealed no other injuries. Based on these findings, we diagnosed the patient with an isolated nutcracker fracture of the cuboid. Using a 1.9 mm arthroscope, we examined the Lisfranc joint. Then the depressed fragments were elevated until the regular joint line was restored. A bone biopsy needle was then used to fill in the large defect with artificial bone. In this case, we did not plate the fracture. Six months after surgery, patient could walk without pain. We report a very rare case of isolated nutcracker fracture of the cuboid. In addition, we suggest our new treatment plan of this fracture.
Seminars in Arthroplasty, Apr 1, 2023
Japan Shoulder Society combined with The 1st Asia-Pacific Shoulder & Elbow Symposium, Sep 25, 2017
Japan Shoulder Society combined with The 1st Asia-Pacific Shoulder & Elbow Symposium, Sep 25, 2017
Journal of Functional Morphology and Kinesiology, Feb 5, 2020
A variation of subscapularis tear has been identified, named floating subscapularis, where the te... more A variation of subscapularis tear has been identified, named floating subscapularis, where the tendon is completely detached from the lesser tuberosity but is continuous with the tissue covering the bicipital groove. An accurate diagnosis can be made using arthroscopic observation with passive external and internal rotation of the affected shoulder, which shows mismatched movement between the humerus and the subscapularis tendon. The purpose of this study is to examine the prevalence of this particular tear pattern. Clinical records during the study period (from January 2011 to December 2017) were retrospectively examined. Overall, 1295 arthroscopic rotator cuff repair procedures were performed. Among these, the subscapularis tendon was repaired in 448 cases, and 27 cases were diagnosed as floating subscapularis. The prevalence of floating subscapularis was 6% in the subscapularis repair population. This particular tear pattern has not previously been described and it seems to be ignored. The floating subscapularis is thought to be the tear of the deep layer preserving the superficial layer connected to the greater tuberosity by fibrous extension of the soft tissue covering the bicipital groove.
Journal of Foot & Ankle Surgery, May 1, 2018
The author reports that he has no conflicts of interest in the authorship and publication of this... more The author reports that he has no conflicts of interest in the authorship and publication of this article.
Arthroscopy, Oct 1, 2019
Purpose: To compare the clinical and imaging outcomes between the suture bridge technique (SB) an... more Purpose: To compare the clinical and imaging outcomes between the suture bridge technique (SB) and the medially based single-row technique (medSR) in patients with 1-to 3-cm tear sizes. Methods: All patients were evaluated preoperatively and postoperatively (at 12 and 24 months) using the modified University of California, Los Angeles scoring system; active range of motion (flexion and external rotation); and a visual analog scale for pain. Healing status was examined by postoperative magnetic resonance imaging. Results: Clinical and imaging evaluations were completed by 92 patients at 1-year follow-up and by 74 patients at 2 years. No significant differences were found between the 2 groups across all measures at final follow-up: The University of California, Los Angeles scores were 33.4 points in SB patients and 33.0 points in medSR patients (P ¼ .58); the visual analog scale scores were 6 mm and 7 mm, respectively (P ¼ .38); the active flexion angles were 161 and 159 , respectively (P ¼ .34); and the external rotation angles were 49 and 52 , respectively (P ¼ .37). Retears were observed in 6.5% of SB patients and 2.1% of medSR patients (P ¼ .31). Medial cuff failure was observed only in SB patients (4.3%, 2 cases), whereas incomplete healing (deep-layer retraction pattern) was observed only in medSR patients (8.7%, 4 cases). Neo-tendon regeneration in the medSR group was observed in 93% of patients. Conclusions: This study did not show any significant differences in the clinical outcomes and cuff integrity between the 2 treatment groups at final follow-up; however, medial cuff failure was observed only in the SB group, and incomplete healing was more frequent in the medSR group. One should consider the risk of medial cuff failure and incomplete healing of the repaired cuff before choosing the repair technique for medium-sized supraspinatus tears.
Japan Shoulder Society combined with The 1st Asia-Pacific Shoulder & Elbow Symposium, Sep 25, 2017
Japan Shoulder Society combined with The 1st Asia-Pacific Shoulder & Elbow Symposium, Sep 25, 2017
Japan Shoulder Society combined with The 1st Asia-Pacific Shoulder & Elbow Symposium, Sep 25, 2017
Jbjs Essential Surgical Techniques, 2021
Background:Arthroscopic rotator cuff repair emerged in the early 1990s, and the single-row repair... more Background:Arthroscopic rotator cuff repair emerged in the early 1990s, and the single-row repair technique (i.e., suture anchor[s] set at the center or laterally on the greater tuberosity) has shown promising outcomes; however, the healing rate of the repaired cuff is suboptimal. Although small to medium-sized rotator cuff tears have shown better clinical outcomes and structural healing than larger tears, healing failure still occurs1.There are several factors that affect rotator cuff healing. The initial stiffness and strength of the repair, gap formation resistance, footprint coverage at the end of surgery, vascularity of the cuff, and mechanical stress on the repaired cuff are important factors2. To improve tendon-to-bone healing, 2 repair techniques have been developed: the suture bridge technique and the medially based single-row technique. The suture bridge technique involves placing anchors in a 2-row fashion, with medial-row sutures from the medial anchors bridged over the footprint with lateral-row knotless anchors3. The single-bridge technique has shown biomechanical superiority in terms of ultimate strength, stiffness, and gap formation resistance4; however, these outcomes are achieved at the cost of relatively high tension at the suture-cuff junction, as well as interference with vascularity at the medial mattress sutures if medial mattress sutures are tied.Alternatively, the medially based single-row technique was proposed as a modification of the laterally based (traditional) single-row technique5. This technique is combined with the creation of bone marrow vents (microfracture technique) lateral to the inserted anchor in the footprint to promote soft-tissue regeneration (called “neotendon”) over the exposed footprint. The theoretical advantages of this technique include lower tension on the repaired cuff; better screw purchase beneath the subchondral bone, which avoids weaker cancellous bone on the peripheral area of the greater tuberosity; and avoidance or reduction of lateral shift of the muscle-tendon junction. However, these outcomes are achieved with relatively weaker initial fixation strength and by exposing the uncovered greater tuberosity footprint lateral to the repaired tendon edge.Both procedures provide equivalent outcomes as measured by functional and pain scores. At present, there is no decisive superiority in treating small to medium-sized supraspinatus tears.Description:Arthroscopic subacromial decompression is performed in both techniques.For suture bridge fixation, the suture anchor is placed at the articular margin of the humeral head as the medial row, and both limbs of each suture are passed through the tendon approximately 5 mm lateral to the muscle-tendon junction of the rotator cuff in a mattress fashion. After the medial-row knots are tied, the suture limbs are brought into 2 lateral push-in anchors.For the medially based single-row repair, suture anchors are placed lateral to the articular margin. Each suture limb is passed through the tendon approximately 1 cm medial to the torn edge of the cuff. All sutures are tied with 7 half-hitches, avoiding a sliding knot.Alternatives:Open or mini-open rotator cuff repair6.Arthroscopic rotator cuff repair suture bridge technique without knot-tying7.Arthroscopic transosseous (i.e., anchorless) rotator cuff repair8.Rationale:The suture bridge technique has achieved better mechanical properties and footprint coverage, and the medially based single-row technique has achieved lower tension on the repaired construct with neotendon regeneration. These techniques are the opposite concept as coverage-oriented and tension-oriented techniques, respectively. To our knowledge, there is presently no study showing that either of these 2 techniques is better than the other4. With that said, the author prefers the medially based single-row technique in cases with degenerative tendon tissue, especially among elderly patients with relatively short tendon substance and with preoperative stiffness because lowering the tension on the repaired construct would be more important than coverage of the greater tuberosity.Expected Outcomes:Published data have not shown significant differences in the clinical outcomes and cuff integrity between these 2 techniques, with no decisive superiority when treating small to medium-sized supraspinatus tears. The choice between these techniques is solely the decision of the surgeon; however, medial cuff failure has been reported only when using the suture bridge technique, and incomplete healing was more frequent among medially based single-row techniques. One should consider the risks of medial cuff failure and incomplete healing of the repaired cuff before choosing the repair technique for medium-sized supraspinatus tears.Important Tips:The proposed risk factors for medial cuff failure in the suture bridge technique include:○ A mattress suture configuration placed at the muscle-tendon junction○ Aggressive rehabilitation○ Use of a large-diameter suture passer○ Application of a sliding knot○ High-stress concentration around the medial knotsThe proposed risk factors for incomplete healing in the medially based single-row techniqueare:○ Lower mechanical properties (initial stiffness and strength, gap formation resistance) in the repaired site○ Lower number of sutures
Archives of Orthopaedic and Trauma Surgery, Dec 14, 2015
Great toe dislocation frequently occurs at the metatarsophalangeal joint. However, an irreducible... more Great toe dislocation frequently occurs at the metatarsophalangeal joint. However, an irreducible dislocation of the great toe interphalangeal (IP) joint due to an accessory sesamoid bone is relatively unusual. A 23-year-old woman suffered a dislocated IP joint of the left great toe. The distal phalanx was plantar subluxated, and the articular surface was misaligned. Ultrasound, magnetic resonance imaging, and computed tomography images did not indicate any factors inhibiting reduction. In addition, the sesamoid bone at the IP joint was found to be rotated in the long-axis direction. The sesamoid bone of the IP joint was hooked from the distal direction and occupied the intercondylar area. IP joint of the left great toe was flexed and the distal phalanx was pushed toward the proximal phalanx during reduction locking with fluoroscopic guidance under local anesthesia, and the dislocation was successfully reduced. The sesamoid bone at the IP joint is anatomically located dorsal to the flexor hallucis longus tendon and volar plate. The sesamoid bone fitted exactly in the distal intercondylar area. The sesamoid bone in our patient could be rotated by forcible plantar flexion of the IP joint displaced proximally and hooked into the intercondylar area from the proximal aspect. Then, the distal phalanx was pulled proximally through the volar plate. This is the first report on a plantar dislocation of the IP joint.
Open access journal of sports medicine, May 1, 2014
Arthroscopy, Apr 1, 2012
The purpose of this study was to examine the histopathologic features of the residual intact tiss... more The purpose of this study was to examine the histopathologic features of the residual intact tissue of a partial articular surface tendon avulsion (PASTA) tear. Methods: In 30 consecutive patients with PASTA lesions, biopsy specimens of the residual tendon were taken. The mean age was 60.4 years (range, 28 to 78 years). All tears were converted to full-thickness tears and arthroscopically repaired. None of the patients were overhead athletes. Samples were histopathologically examined and graded by use of a modified semiquantitative scale (between 0, normal appearance, and 21, most abnormal appearance). Data were analyzed by multiple regression analysis to estimate the effect of aging, smoking status, duration of pain, and steroid injections. Results: Degenerative changes were evident in 28 of 30 cases (93%). The mean score on the modified semiquantitative grading scale was 10.5 (range, 3 to 16; SD, 2.6). Multiple regression analysis failed to show a statistically significant correlation between the score on the modified semiquantitative grading scale and aging, smoking status, duration of pain, or steroid injections. Conclusions: Over 90% of the macroscopically intact residual tendon tissues of the PASTA lesions showed moderate histopathologic degeneration. Level of Evidence: Level IV, therapeutic case series.
Shoulder & Elbow, Dec 13, 2021
UHMWPE suture shows excellent biocompatibility and complication associated with suture debris had... more UHMWPE suture shows excellent biocompatibility and complication associated with suture debris had not been described before in shoulder surgery. In this study, a case of a 38-year-old man with a wear debris pseudotumor mimicking osteochondromatosis in the subacromial bursa five years after arthroscopic rotator cuff repair using a composite braid suture (a polydioxanone core with a sleeve of UHMWPE) was presented. Histological examination confirmed the presence of suture fragments surrounded with the osteochondral layer without inflammatory reactions. The present study implies the potential risk of free fragmented remnants from the UHMWPE suture. Because of the silent nature of the histological response, a high index of suspicion should be necessary to disclose the chanciness of its use.
Journal of Functional Morphology and Kinesiology, Nov 1, 2016
The purpose of this study was to evaluate the relationship between spine alignment and shoulder e... more The purpose of this study was to evaluate the relationship between spine alignment and shoulder elevation in a kyphotic elderly population. Twenty-three consecutive female patients who underwent balloon kyphoplasty for spinal compression fractures without shoulder symptoms were examined (mean age, 76 ± 6.3 years). Thoracic kyphosis angle (TK), lumbar lordosis angle (LL), and pelvic tilt angle (PT) were measured on standing true lateral radiographs of the whole spine. The shoulder active range of motion with or without scapular fixation was measured in the sitting position. The University of California Los Angeles (UCLA) Shoulder Score was recorded as the functional evaluation. The total elevation angle was 128.9 • ± 22 • , the glenohumeral angle was 80.7 • ± 10.9 • , and the UCLA Shoulder Score was 32.4 ± 2.1. The TK was 36.7 • , the LL was −29.1 • , and the PT was 30.5 •. The total elevation angle was significantly negatively correlated with LL. TK and PT were not significantly correlated with any parameter. The total shoulder elevation angle was limited in the kyphotic elderly women in this study, and kyphotic change appeared to interfere with spinal extension and reduced the total elevation arc with no glenohumeral motion deficit. A reduction in total shoulder elevation was negatively correlated with LL.
Journal of Orthopaedic Science, Sep 1, 2011
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Papers by Kotaro Yamakado