Republication of "Mucous Cyst at the Interphalangeal Joint of the First Toe Caused by Contact Pressure With the Second Toe due to Hallux Valgus: A Case Report".

A 77-year-old woman presented with a mucous cyst on the lateral aspect of the interphalangeal joint of the first toe caused by contact pressure with the second toe from hallux valgus. She complained of discomfort and discharge from the left first toe for approximately 4 months. Physical examination showed the second toe pressing strongly against the first toe due to hallux valgus and discharge from the skin on the lateral aspect of the interphalangeal joint of the first toe. Magnetic resonance imaging showed a cystic lesion at the same level. The patient underwent a modified scarf osteotomy of the first metatarsal for hallux valgus to resolve the contact pressure between the toes-considered the cause of the mucous cyst-and resection of mucous cyst. Forefoot weight bearing was allowed 6 weeks after surgery. As of 1 year after surgery, she has had no recurrence of the cyst. The score on the Japanese Society for Surgery of the Foot hallux metatarsophalangeal-interphalangeal scale improved from 59/100 points to 92/100. This outcome suggests that hallux valgus correction should be considered when a mucous cyst is associated with contact pressure due to a hallux valgus deformity. To the best of our knowledge, there are no previous reports of a mucous cyst caused by contact pressure between the first toe and second toe due to hallux valgus.

Republication of "Gelatinous Transformation of Bone Marrow in the Calcaneus, Diagnosed by Open Bone Biopsy in a Patient With Anorexia Nervosa: A Case Report".

Gelatinous transformation of bone marrow (GTBM) is a complication of various diseases, one of which is anorexia nervosa (AN). We describe a rare case of a 20-year-old man who presented to our clinic with a 3-month history of heel pain without trauma. At presentation, he was noted to have a low body mass index (BMI) of 16.2 kg/m2 and pancytopenia. On magnetic resonance imaging, the left calcaneus showed low intensity on T1-weighted and high intensity on T2-weighted images. Open biopsy was done because we suspected that the lesion was either a lymphoproliferative tumor or a trabecular-type bone metastatic tumor. However, tissue histology of bone samples showed atrophy of fat cells with deposition of gelatinous material and a decreased hematopoietic cell population. Therefore, we made a diagnosis of GTBM, most likely caused by AN. We started treatment with nutritional support, and 6 months later, the hematological parameters returned to normal and BMI improved to 19.4 kg/m2. He was able to return to work and had no left heel pain. This case indicates that foot and ankle surgeons need to be aware of this rare pathology, although it might be difficult to diagnose without biopsy. To our knowledge, very few descriptions of GTBM in the calcaneus have been reported to date.

Influence of the glenoid baseplate position on the direction and length of the superior and inferior locking screws.

Introduction : Superior screw insertion in reverse shoulder arthroplasty (RSA) carries the potential risk of suprascapular injury. The purpose of this study was to evaluate how the baseplate position affects the superior screw position and length in RSA. Methods : Three-dimensional (3D) computer simulation models of RSA were established using computed tomography data of baseplates with superior and inferior screws and 3D scapular models from 10 fresh cadavers. Superior screw position, the distance from the superior screw hole to the suprascapular notch, and the screw lengths were measured and compared among various baseplate positions with two inferior tilts (0 and 10 degrees) and three rotational patterns (11-5, 12-6, and 1-7 o'clock in the right shoulder). Results : For the 1-7 o'clock / inferior tilt 0 degrees baseplate, the superior screw located anterior to the SS notch in all shoulders, the distance to the SS notch was the longest (12.8 mm), and the inferior screw length was the shortest (23.1 mm). Conclusion : Although there is a concern of a short inferior screw length, initial fixation using a baseplate with 1-7 o'clock rotation and an inferior tilt of 0 degrees appears preferable for SS nerve injury prevention during superior screw insertion. J. Med. Invest. 69 : 185-190, August, 2022.

Implications of Dorsalis Pedis Artery Anatomical Variants for Dorsal Midfoot Surgery.

BACKGROUND: The dorsalis pedis artery (DPA) usually branches into the arcuate artery (AA) from its lateral side which in turn crosses the bases of the lateral four metatarsals. The DPA then passes into the first interosseous space, where it divides into the first metatarsal artery and the deep plantar artery. In this study, we aimed to determine the extent of variation in the DPA and the distance between the AA and the tarsometatarsal (TMT) joint with the aim of reducing the risk of vascular complications arising from dorsal midfoot surgery. METHODS: In 29 fresh cadaveric feet, we examined the course of the DPA and the distance between the AA and the TMT joint on computed tomography images with barium sulfate contrast. RESULTS: The DPA was observed to have a standard course in 11 of the 29 cases (37.9%) but did not give rise to the AA and lateral tarsal artery or branches of the plantar arterial arch supplying to the second to fourth metatarsal spaces in 10 of 29 cases (34.5%). The mean closest distance from the TMT joint to the AA at the second, third, and fourth metatarsal level in the sagittal plane was 11.4, 14.6, and 17.1 mm, respectively. CONCLUSION: We found substantial variation in the arterial anatomy of the DPA system across the dorsal midfoot. CLINICAL RELEVANCE: The risk of pseudoaneurysm and frank arterial disruption may be mitigated if the surgeon is aware of the variations of the course of the DPA when performing dorsal midfoot surgery.

Flexor tenotomy for mallet toe with penetration of the middle phalanx head by dual-component intramedullary implant following proximal interphalangeal arthrodesis.

INTRODUCTION: There is a risk of mallet toe following proximal interphalangeal (PIP) joint fusion for hammertoe. Here we describe a rare case of penetration of the dorsal aspect of the middle phalanx head by the distal portion of a dual-component intramedullary implant during progression of mallet toe that was treated with flexor tenotomy. PRESENTATION OF CASE: A 59-year-old man underwent uneventful arthrodesis of the third PIP using a dual-component intramedullary implant and presented 6 months later with progressive mallet toe and swelling, pain, and ulceration over the distal interphalangeal joint of the third toe. Imaging showed that the distal portion of the implant had penetrated the dorsal aspect of the middle phalanx head. A longitudinal incision was made over the dorsum of the middle and proximal phalanges of the third toe and the implant was removed. A plantar incision was made at the metatarsophalangeal joint and the flexor tendon was cut to correct the mallet toe deformity. One year later, correction was satisfactory with an acceptable functional outcome and good pain relief. DISCUSSION: We successfully treated a man with penetration of the dorsal border of the middle phalanx head in the third toe by the distal portion of a dual-component intramedullary implant as a result of mallet toe that developed following PIP arthrodesis, by removing the implant and performing flexor tenotomy. CONCLUSION: Addition of flexor tenotomy should be considered when performing PIP arthrodesis in a patient with risk factors for severe mallet toe.

Relationship Between the Lateral Plantar Artery and the Retrograde Intramedullary Nail During Tibiotalar and Subtalar Arthrodesis: A Fresh Cadaveric Study.

BACKGROUND: Tibiotalocalcaneal (TTC) arthrodesis with retrograde intramedullary nailing has become established. Iatrogenic injury to the vasculature (eg, lateral plantar artery [LPA] pseudoaneurysm) during insertion of the nail has been reported. The aim of this study was to identify the safe zone that avoids injury to the LPA during TTC arthrodesis. METHODS: The retrograde lateral curved nail entry point should be in line with the midpoint of the tibial medullary canal and the lateral column of the calcaneus. Enhanced 3-dimensional computed tomography scans of 26 fresh cadaveric feet were assessed. The closest distance between the LPA and the edge of the nail entry point was measured in the plantar view. RESULTS: The closest mean distance between the LPA and the edge of the nail entry point was 6.7 mm for all 26 feet, 12.8 mm for 3 feet (11.5%) in which the LPA did not cross the medial wall of the calcaneus, 8.1 mm for 9 (34.1%) in which the point where the LPA crossed the medial wall of the calcaneus was anterior to the center of the nail entry point, and 4.2 mm for 14 (53.8%) feet in which this point was posterior to the center of the nail entry point. CONCLUSIONS: Care should be taken to avoid the LPA during reaming at the nail entry point, especially when the point where the LPA crosses the medial wall of the calcaneus is posterior to the center of the nail entry point. LEVELS OF EVIDENCE: IV, cadaveric study.

Examination of Safe Zone to Avoid Injury of the Lateral Plantar Artery During Calcaneal Osteotomy: A Fresh Cadaveric Study.

BACKGROUND: Calcaneal osteotomy are used to treat various pathologies in the correction of hindfoot deformities. But lateral plantar artery (LPA) pseudoaneurysms have been reported following calcaneal osteotomy, and LPA pseudoaneurysms may be at risk for rupture. Although the vascular structures in close proximity to calcaneal osteotomies have variable courses and branching patterns, there is little information on safe zone for LPA during calcaneal osteotomy. The aims of this study were to identify the safety zone to avoid the LPA injury during calcaneal osteotomy. METHODS: Enhanced computed tomography scans of 25 fresh cadaveric feet (male, n = 13; female, n = 12; mean age 79.0 years at the time of death) were assessed. The specimens were injected with barium via the external iliac artery. Line A is the landmark line and extends from the posterosuperior aspect of the calcaneal tuberosity to the plantar fascia origin, and the perpendicular distance between the LPA and line A at its closest point was measured on sagittal images. RESULTS: The average perpendicular distance between the LPA and line A at its closest point was 15.2 ± 2.9 mm. In 2 cases (8.0 %), the perpendicular distance between the LPA and line A at its closest point was very close, approximately 9 mm. In 18 of 25 feet (72.0%), the point where perpendicular distance from the line A to LPA is the closest was the bifurcation of one of the medial calcaneal branches from LPA, and in 7 feet in 25 feet (28.0%) feet the point where perpendicular distance from the line A to LPA is the closest was the trifurcation of LPA, medial plantar artery, and one of the medial calcaneal branches. CONCLUSIONS: Calcaneal osteotomy approximately more than 9 mm from the line A could injure the LPA in overpenetration into the medial aspect of tcalcaneal osteotomy. Completion of the osteotomy on the medial side should be performed with caution to avoid iatrogenic injury of the LPA. LEVELS OF EVIDENCE:: Level IV, Cadaveric study.

One-stage tibial deformity correction and ankle arthrodesis for ankle osteoarthritis and tibial malalignment after low tibial osteotomy.

INTRODUCTION: There are no reports on one-stage corrective tibial opening wedge osteotomy and arthrodesis for osteoarthritis of the ankle and tibial malalignment after distal tibial osteotomy. PRESENTATION OF CASE: The patient was a 70-year-old woman who presented with complaints of ankle pain and lower limb deformity after tibial osteotomy performed for ankle arthritis 17-18 years earlier. Clinical examination revealed marked swelling around the ankle joint and pain and tenderness at the joint line. Imaging showed tibial malalignment and severe osteoarthritic changes in the ankle. The patient had valgus deformity of 21° and recurvatum deformity of 4°. In two months, she admitted to Department of Orthopedics at Tokushima University Hospital in Japan and we performed one-stage corrective tibial opening wedge osteotomy and ankle arthrodesis with an anterolateral plate through a lateral longitudinal incision. After removal of the previous implants, the remaining articular cartilage and osteophytes were removed from the tibial and talar surfaces. After debridement of the talar trochlea and tibial plateau, the center of rotation and angular deformity of the tibia was cut transversely and a 1-cm bone graft obtained from the removed fibula was inserted into the osteotomy site, which decreased the tibial malalignment. An anterolateral locking plate was inserted over the anterior and lateral sides of the tibia, and the ankle was fused using 2 cannulated screws. DISCUSSION: The patient wore an above-knee splint for 6 weeks to avoid weight-bearing followed by gradual weightbearing with a brace thereafter. Osseous fusion was achieved after about 3.5 months. Radiographs obtained at the 2-year follow-up visit showed complete union of the tibia and talus. Full correction of valgus and recurvatum deformity was achieved, and the patient was able to perform daily activities with almost no pain. CONCLUSION: We reported a rare case of ankle osteoarthritis and tibial malalignment that was successfully treated with one-stage corrective tibial opening wedge osteotomy and ankle arthrodesis using an anterolateral plate via a transfibular approach.

The Effect of Single vs Serial Platelet-Rich Plasma Injections in Osteochondral Lesions Treated With Microfracture: An In Vivo Rabbit Model.

BACKGROUND: Biological adjuvants are used after a musculoskeletal injury to improve healing, decrease inflammation, and restore joint homeostasis. Work on 1 such adjuvant, platelet-rich plasma (PRP), has suggested a positive effect when introduced during cartilage repair. However, it remains unknown whether healing osteochondral injuries benefit from serial PRP injections. PURPOSE: To evaluate the effects of serial PRP injections versus a single PRP injection on reparative cartilaginous tissue, subchondral bone remodeling, and the expression of inflammatory cytokines in joint synovium. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 48 New Zealand White rabbits were randomly assigned to receive 1 (1P), 2 (2P), or 3 (3P) PRP injections. Cylindrical full-thickness cartilage defects (2.9 × 2.9 mm) with microdrillings (0.6-mm diameter) were created on the medial condyles of both knees. PRP was injected into the right knee after closure (groups 1P, 2P, and 3P), at 2 weeks after surgery (groups 2P and 3P), and at 4 weeks after surgery (group 3P). The left knees did not receive any PRP injections. A total of 6 rabbits in each group were euthanized at 3, 6, and 12 weeks postoperatively. Cartilage repair tissue was assessed using the Goebel macroscopic and modified International Cartilage Regeneration & Joint Preservation Society (ICRS) histological scoring systems. Subchondral bone remodeling was evaluated by micro-computed tomography analysis (micro-CT). Inflammatory cytokine levels were assessed by quantitative polymerase chain reaction. RESULTS: No significant differences were found for the mean macroscopic score between the PRP groups at 12 weeks (control, 6.1 ± 3.3; group 1P, 3.4 ± 2.7; group 2P, 4.2 ± 2.9; group 3P, 0.7 ± 1.5). All PRP groups had a significantly higher mean modified ICRS histological score compared with the control group, but no significant difference was found among the PRP groups. No significant differences were seen in outcomes for the tested micro-CT parameters or cytokine expression levels. CONCLUSION: Serial PRP injections conferred no apparent advantage over single injections according to evaluations of the macroscopic and histological appearance of the cartilaginous tissue, subchondral bone healing, and inflammatory cytokine expression levels in the synovium. CLINICAL RELEVANCE: The use of PRP as a biological adjuvant to bone marrow stimulation for osteochondral lesions has the potential to enhance the quality of regenerative cartilaginous tissue. We recommend only a single PRP injection if the use of PRP is indicated by the operating surgeon as an adjuvant therapy for osteochondral lesions.

Temporary Kirschner wire fixation of the first metatarsophalangeal joint before osteotomy for hallux valgus.

INTRODUCTION: Numerous operative procedures have been described for correction of hallux valgus, including distal step-cut osteotomy such as the Mitchell osteotomy. However, overcorrection can occur due to technical problems with the initial metatarsal osteotomy. Here, we describe a modified Mitchell osteotomy with a novel method, the temporary Kirschner wire fixation of the first metatarsophalangeal joint (TeKFiM) method (Tonogai method), that can be used before osteotomy for hallux valgus to avoid incongruency and overcorrection. OPERATIVE TECHNIQUE: A skin incision and Y-shaped capsulotomy are performed and the medial exostosis is excised. Lateral capsule release is done if the first metatarsophalangeal (MTP) joint cannot be reduced manually. Next, a Kirschner wire (K-wire) is inserted subcutaneously through the medial side of the first proximal phalanx to the lateral side of the first metatarsal to preserve the correct congruency of the first MTP joint during surgery. To correct pronation of the distal fragment, step-off transverse cuts are made in the distal fragment, as described by Mitchell, reaching one-second to two-thirds of the transverse diameter of the neck from the plantar medial side. After the osteotomies are completed, the lateral spike of the proximal fragment is flattened. The distal fragment is displaced laterally and slightly plantarward, and the pronation deformity of the distal fragment is corrected by inserting a K-wire to act as a joystick. The osteotomy site is stabilized using two Herbert-type screws. After removal of the K-wire, the operation is completed by closing the medial capsule of the first MTP joint and the skin. A plantar cast is applied for 2 weeks, followed by a special heel brace for 4-6 weeks. Sutures are removed 2 weeks after surgery. Patients are allowed to start weightbearing gradually as tolerated from 2 weeks after surgery. DISCUSSION: After osteotomy, it is difficult to maintain the correct congruency of the first MTP joint due to instability of the distal fragment. The TeKFiM method (Tonogai method) reliably maintains this congruency during surgery. Also, by using a K-wire as a joystick to fix the joint in correct congruency, the first toe is rotated and pronation is corrected by supinating the distal fragment. The K-wire also serves as a landmark for determining how far the distal fragment is shifted plantarward. CONCLUSIONS: We have developed a modified Mitchell osteotomy with the novel TeKFiM method (Tonogai method) before osteotomy for hallux valgus to avoid incongruency and overcorrection. This method also provides a landmark to correct pronation and plantarward shifting.

A case of ankle osteoarthritis associated with lateral premalleolar bursitis caused by chronic ankle instability.

INTRODUCTION: Lateral premalleolar bursitis develops on the dorsolateral aspect of the foot anterior to the lateral malleolus, distinct from lateral malleolar bursitis located just around the lateral malleolus. PRESENTATION OF CASE: A 71-year-old woman visited an orthopedic clinic about 40 years after an episode of ankle sprain and was diagnosed with lateral premalleolar bursitis and osteoarthritis of the left ankle. Stress radiography revealed left ankle anterolateral malleolar bursitis with varus and anterior instability. We opted for less invasive arthroscopic ankle arthrodesis over open resection to stop the communication of the bursitis with the ankle joint. The lateral premalleolar bursitis was located just over the anterolateral portal. The remaining cartilage in the talotibial joint was removed and the subchondral surface was exposed and curetted down to a bleeding surface by ankle arthroscopy. The talotibial joint was fixed with 3 6.0-mm cannulated cancellous screws. The foot and ankle were immobilized by cast for 4 weeks. Bony union was achieved about 8 weeks postoperatively. The patient could perform daily activities without pain and with no recurrence of the lateral premalleolar bursitis at the 1.5-year follow-up. DISCUSSION: To our knowledge, this is the first report on arthroscopic arthrodesis for ankle osteoarthritis with recalcitrant lateral premalleolar bursitis caused by the check valve mechanism of chronic ankle instability after old ankle sprain. CONCLUSION: We report a case of arthroscopic arthrodesis for osteoarthritis of the ankle associated with lateral premalleolar bursitis caused by the check valve mechanism of chronic ankle instability after old ankle sprain.

Posterior ankle arthroscopy for posterior ankle synovitis with an enlarged posterior talar process caused by a cat bite or scratch: A case report.

INTRODUCTION: Legs are sometimes infected and swollen by cat bite or scratch. However, there is no report of synovitis with an enlarged talar posterior process in the posterior ankle caused by a cat bite or scratch which was treated by removal of the enlarged process and synovectomy with release of the flexor hallucis longus tendon via posterior ankle arthroscopy. PRESENTATION OF CASE: The patient was a 58-year-old woman who had started keeping a cat 7 months earlier. She subsequently sustained cat bite and scratch wounds to her lower legs, which gradually became increasingly swollen. On presentation, there was left lower leg swelling, particularly on the posterior aspect of the ankle. Imaging revealed bone marrow edema in the enlarged posterior talar process and inflammation of the adjacent soft tissue. We excised the enlarged posterior talar process, performed synovectomy, and released the flexor hallucis longus tendon using a posterior arthroscopic technique via standard posterolateral and posteromedial portals. Microbial culture was negative. DISCUSSION: The patient returned to daily activities approximately 3 weeks after arthroscopic debridement. There was no recurrence at the 1-year follow-up visit. To our knowledge. CONCLUSION: We report a rare case of posterior ankle synovitis with an enlarged posterior talar process caused by a cat bite or scratch which was treated successfully by posterior ankle arthroscopic debridement.

Arthrodesis for chronic lateral subtalar joint dislocation caused by posterior tibial tendon dysfunction: A case report.

INTRODUCTION: Adult acquired flatfoot deformity (AAFD) caused by posterior tibial tendon dysfunction (PTTD) can lead to the development of peritalar subluxation (PTS) and much more rarely to lateral subtalar dislocation. PRESENTATION OF CASE: A 75-year-old woman was referred to our hospital with an approximately 15-year history of pain in her right foot without obvious trauma. The lateral shifting foot deformity had worsened in the previous 5 years. On presentation, she had tenderness over the talonavicular joint, and the skin overlying the talar head on the medial foot was taut. Imaging revealed lateral displacement of the calcaneus with simultaneous dislocation of the talonavicular and talocalcaneal joints. We diagnosed lateral subtalar dislocation including the talonavicular and talocalcaneal joints caused by PTTD, which we treated by reduction and fusion of the subtalar joint complex. The foot and ankle were immobilized with a cast for 6 weeks. DISCUSSION: At the 1-year follow-up visit, the patient reported no pain during daily activities, although flatfoot persisted. CONCLUSION: We report a rare case of chronic lateral subtalar dislocation caused by PTTD that was treated by fusion of the talonavicular and talocalcaneal joints.

A case of osteophyte excision and arthroscopic arthrodesis for tarsal tunnel syndrome with traumatic osteoarthritis of the ankle.

INTRODUCTION: There are some reports of tarsal tunnel syndrome (TTS) entrapment/impingement from bony factors, including exostosis and fragment, but there are no reports on TTS with traumatic osteoarthritis of the ankle that were treated with osteophyte excision for TTS and arthroscopic arthrodesis for osteoarthritis of the ankle. PRESENTATION OF CASE: A 61-year-old woman with left trimalleolar fracture had undergone surgery 3 years earlier and was referred to our hospital for further investigation of persistent left ankle pain and numbness around the left medial malleolus and plantar aspect of the foot. Clinical examination demonstrated plantar hypesthesia and a positive Tinel's sign at the tarsal tunnel. Imaging showed severe osteoarthritic change in the ankle and an osteophyte of the posteromedial distal tibia that appeared to be impinging on the tibial nerve. We performed arthroscopic ankle arthrodesis, which is less invasive than the open procedure, with removal of the osteophyte as the cause of TTS. Tarsal tunnel exploration revealed a large osteophyte pushing on the tibial nerve, and the osteophyte was removed. DISCUSSION: About 8 weeks after surgery, bony union was achieved. At the 2-year follow-up visit, the patient could perform daily activities with almost no pain or numbness. This case offers further insight into the management of TTS with traumatic osteoarthritis of the ankle. CONCLUSION: We report here successful treatment of a rare case of tarsal tunnel syndrome (TTS) accompanied with traumatic osteoarthritis of the ankle, treated with osteophyte excision for the TTS and arthroscopic for the osteoarthritis.

A case of arthroscopic ankle arthrodesis for hemophilic arthropathy of the bilateral ankles.

INTRODUCTION: Hemophilic arthropathy can affect multiple joints including ankle. However, only one report has been published regarding both arthroscopic ankle arthrodesis with hemophilic arthropathy. PRESENTATION OF CASE: The patient was a 23-year-old man with hemophilia A and a 3-year history of recurrent hemarthrosis in both ankles. We undertook surgery to treat arthropathy. His left ankle was treated first and the right ankle 6 months later. In both ankles, the cartilage was worn and eburnated. The remaining cartilage was removed and more dimples were created to fuse the tibia and talus. The ankle was fixed using 3 cannulated screws. Postoperatively, the patient wore an immobilization cast with no weight-bearing for 2 weeks. Thereafter, weight-bearing was allowed and the cast was removed 4 weeks after surgery. DISCUSSION: At the 1-year follow-up, bony union was satisfactory, functional outcome was acceptable, and pain relief was good. The Japanese Society for Surgery of the Foot ankle-hindfoot scale score increased from 24 preoperatively to 87 postoperatively. CONCLUSION: We report successful treatment with arthroscopic arthrodesis in a case of hemophilic arthropathy in both ankles.

Posterior Ankle Arthroscopy for Osteochondromatosis of the Posterior Ankle Extra-Articular Space with a Longitudinal Tear of Flexor Hallucis Longus.

We report a rare case of osteochondromatosis of the posterior ankle extra-articular space with a longitudinal tear of flexor hallucis longus (FHL). A 77-year-old woman was referred to our hospital with an approximately 4-year history of pain and swelling in the right posterior ankle joint without obvious trauma. The pain had worsened in the previous 2 years. On presentation, she had tenderness at the posteromedial and posterolateral ankle. Imaging revealed several ossified loose bodies in the posterior ankle extra-articular space. We removed the loose bodies, performed tenosynovectomy around the FHL, and released the FHL tendon using a posterior arthroscopic technique via standard posterolateral and posteromedial portals. A longitudinal tear and fibrillation were detected in the FHL. The patient was able to return to her daily activities approximately 3 weeks after surgery. At the 1-year follow-up visit, she continued to have minor discomfort and slight swelling on the posteromedial aspect of the right ankle but had no recurrence of the ossified loose bodies. To our knowledge, this is the first report of osteochondromatosis of the posterior ankle extra-articular space with a longitudinal tear of the FHL that was treated by removal of loose bodies, tenosynovectomy around the FHL, and release of the FHL tendon via posterior ankle arthroscopy.

Posterior Arthroscopic Treatment of a Massive Effusion in the Flexor Hallucis Longus Tendon Sheath Associated with Stenosing Tenosynovitis and Os Trigonum.

We report a rare case of massive accumulation of fluid in the flexor hallucis longus tendon sheath with stenosing tenosynovitis and os trigonum. A 34-year-old woman presented to our hospital with pain and swelling in the posteromedial aspect of the left ankle joint after an ankle sprain approximately 8 months earlier. There was tenderness at the posteromedial aspect of the ankle, and the pain worsened on dorsiflexion of the left great toe. Magnetic resonance imaging revealed massive accumulation of fluid around the flexor hallucis longus tendon. We removed the os trigonum, performed tenosynovectomy around the flexor hallucis longus, and released the flexor hallucis longus tendon via posterior arthroscopy using standard posterolateral and posteromedial portals. At 1 week postoperatively, the patient was asymptomatic and able to resume her daily activities. There has been no recurrence of the massive accumulation of fluid around the flexor hallucis longus tendon as of 1 year after the surgery. To our knowledge, this is a rare case report of extreme massive effusion in the flexor hallucis longus tendon sheath with stenosing tenosynovitis and os trigonum treated successfully by removal of the os trigonum, tenosynovectomy around the flexor hallucis longus, and release of the flexor hallucis longus tendon via posterior ankle arthroscopy.

The Origin of the Anterior Lateral Malleolar Artery From the Anterior Tibial Artery: A Fresh Cadaveric Study.

The anterior lateral malleolar artery (ALMA), which usually originates from the anterior tibial artery (ATA), courses transversely and laterally, passing under the extensor digitorum longus and peroneus tertius tendons. Variations in the origin of the ALMA from the ATA can occur. Branches of the ATA, such as the ALMA, are prone to pseudoaneurysm. This study reviewed the origin of the ALMA from the ATA and aimed to identify problems in anterior ankle arthroscopy that might cause injury to the ALMA. Enhanced computed tomography scans of 24 feet of 24 fresh cadavers (13 males, 11 females; average age 78.1 years) were assessed. The limb was injected with barium sulfate suspension through the external iliac artery; the origin of the ALMA from the ATA on the sagittal plane was recorded. The origin was at the ankle joint level in 4 specimens and below the ankle joint in 17 specimens. The distance from the ankle joint to the branching point of the ALMA on the sagittal plane was 5.2 mm distal to the joint. The level of origin of the ALMA from the ATA was established. Instruments should not be inserted from the distal direction when placing anterolateral portals. Levels of Evidence: Level IV, cadaveric study.

Joint distraction force changes the three-dimensional articulation of the femur and tibia in total knee arthroplasty: a cadaveric study.

PURPOSE: The purpose of this study was to test the hypotheses that the joint distraction force changes the three-dimensional articulation between the femur and the tibia and that the presence of posterior cruciate ligament (PCL) affects the three-dimensional articulation during joint gap evaluation in total knee arthroplasty (TKA). METHODS: Cruciate-retaining TKA procedures were performed on 6 cadaveric knees using a navigation system. The joint center gap and varus ligament balance were measured using Offset Repo-Tensor® with the knee at 90° of flexion before and after PCL resection for joint distraction forces of 89, 178, and 266 N. The three-dimensional location of the tibia relative to the femur and the axial rotational angle of the tibia were also assessed. RESULTS: Regardless of PCL resection, the joint center gap became larger (p = 0.002, p = 0.020) and varus ligament balance became more varus (p = 0.002, p = 0.002) with increasing joint distraction force, whereas the tibia was more internally rotated (p = 0.015, p = 0.009) and more anteriorly located (p = 0.004, p = 0.009). The tibia was more internally rotated (p = 0.015) and more posteriorly located (p = 0.026) after PCL resection than before resection. CONCLUSIONS: Joint distraction force changed three-dimensional articulation regardless of PCL preservation. PCL function was revealed as a factor restraining both tibial posterior translation and internal rotation. Surgeons should recognize that joint gap evaluation using a tensor device is subject to three-dimensional changes depending on the magnitude of the joint distraction force.

Rotational and varus-valgus laxity affects kinematics of the normal knee: A cadaveric study.

PURPOSE: The aim of this study was to evaluate the relationship between soft tissue laxity and kinematics of the normal knee using a navigation system. METHODS: Fifteen cadaveric knees from 11 fresh frozen whole-body specimens were included in this study. The navigation system automatically recorded the rotation angle of the tibia as the internal-external (IE) kinematics and the coronal alignment of the lower limb as the varus-valgus (VV) kinematics. These measurements were made with the joint in maximal extension, at 10° intervals from 0° to 120° of flexion, and at maximal flexion during passive knee motion. For evaluation of laxity, the examiner gently applied maximum manual IE and VV stress to the knee at 0°, 30°, 60°, and 90° of flexion. RESULTS: The measurements showed almost perfect reliability. The mean correlation coefficient between the intraoperative tibial rotation angle and the intermediate angle of IE laxity was 0.82, while that between the coronal alignment of the lower limb and the intermediate angle of the VV laxity was 0.96. There was a statistically significant correlation between kinematics and laxity at all degrees of knee flexion. CONCLUSION: The present study revealed that the rotation angle of the tibia was correlated to the intermediate angle of IE laxity at 0°, 30°, 60°, and 90° of knee flexion and the coronal alignment of the lower limb also correlated to the intermediate angle of VV laxity. These findings provide important reference data on soft tissue laxity and kinematics of the normal knee.