The Correction Potential of the Lateral Release of the Hallux Valgus: A Comparative Anatomical Study of Minimally Invasive Versus Open Surgical Technique Using a Dorsal Approach.

Background: Lateral release (LR) is an integral part of surgical correction of hallux valgus. A comparison was made between the open and minimally invasive LR techniques using a dorsal approach. The reliability and safety of the two methods were compared. Besides, the release of specific structures was investigated with special emphasis on ascertaining if the release was partial or a total one. Methods: In this study on cadavers, LR was performed on nine pairs of foot and ankle specimens. The group assignments were randomized for each case. The operations were followed by anatomical preparation, data collection, photo documentation, and statistical analysis. Results: A statistically significant advantage was observed with the open dorsal approach as there was a complete release of the adductor hallucis muscle from the lateral sesamoid and the lateral metatarsosesamoid ligament (p = 0.015 in each case). In terms of releasing the adductor hallucis muscle from the proximal phalanx, the lateral joint capsule, and the lateral collateral ligament, none of the investigated procedures showed better performance. However, open dorsal access tends to show a higher degree of release more frequently. Conclusions: Splitting of the lateral joint capsule, including the lateral collateral ligament and lateral metatarsosesamoid ligament via the dorsal approach can be performed reliably and completely using the open surgical technique. The open dorsal technique shows better rates of detachment when the adductor hallucis muscle is released from the lateral sesamoid. Both techniques resulted in incomplete release of the adductor hallucis muscle from the proximal phalanx. Study Type: Therapeutic-investigating the results of a treatment. Level of Evidence: II (Prospective cohort study). Supplementary Information: The online version contains supplementary material available at 10.1007/s43465-021-00575-3.

Iatrogenic Damage to Neurovascular and Soft Tissue Structures During Lateral Release of Hallux Valgus: A Comparative Anatomical Study of Minimally Invasive Versus Open Surgical Techniques.

Lateral release is often an integral step in surgical correction of hallux valgus and can be performed using open or minimally invasive techniques. We investigated whether these techniques cause iatrogenic damage to arteries, nerves, tendons, or joint capsules. In this cadaver study, lateral release was performed on 9 pairs of specimens by a specialized foot surgeon. The specimens were randomly assigned to each group. The operations were followed by anatomical preparation, data collection, photo documentation, and statistical analysis. Iatrogenic damage to arteries, nerves, tendons, or joint capsules was rare, regardless of the surgical technique used. However, with the minimally invasive technique, the tendon of the extensor hallucis longus muscle and the sensitive terminal branches of the fibular nerve were at risk due to their anatomical proximity to the access portal. The deep transverse metatarsal ligament was potentially at risk if the adductor hallucis muscle was completely detached from the lateral sesamoid. When the deep transverse metatarsal ligament was transected there was risk of damaging the underlying plantar neurovascular structures. Both surgical techniques are safe in terms of the risk of injury to neighboring neurovascular and soft tissue structures.

[Cartilage chip transplantation for cartilage defects of the first metatarsophalangeal joint]. / Minced Cartilage bei Knorpeldefekten am Großzehengrundgelenk.

OBJECTIVE: Treatment of circumscribed cartilage defects in the first metatarsophalangeal joint (MTP1) using autologous cartilage fragments. INDICATIONS: Full thickness cartilage defects (ICRS IV) or focal osteoarthritis in combination with hallux rigidus. CONTRAINDICATIONS: Pre-existing ankylosis of the metatarsophalangeal joint; global osteoarthritis of the joint; advanced osteoarthritis of the sesamoidal articulation; osteonecrotic cysts in the head of the first metatarsal bone. SURGICAL TECHNIQUE: Preparation of the metatarsophalangeal joint. Mobilization of the first metatarsal head. Harvesting of the cartilage fragments from the dorsal rim portion as part of the cheilectomy. Mincing the cartilage fragments with a 3.0 mm shaver in sterile conditions. Augmenting the cartilage fragments with autologous conditioned plasma (ACP). Preparing the defect area and creation of a "contained" defect. Replantation of the resulting minced cartilage mass into the defect of the articular surface on the first metatarsal head. POSTOPERATIVE MANAGEMENT: Immobilization of the MTP1 for 48 h. Intensive physiotherapy for 3 months. Full weight bearing after reduced swelling. RESULTS: In 2020, 5 patients were treated with the method described and followed up for a period of 1 year. All patients were subjectively satisfied with the result of the operation. There were no relevant surgery-associated complications.

[Description of a technique that uses Lapidus arthrodesis plus osteochondral autotransplantation in the treatment of severe hallux rigidus]. / Lapidusarthrodese in Kombination mit einer osteochondralen Autotransplantation in das Metatarsale-I-Köpfchen zur Behandlung der fortgeschrittenen Arthrose des Großzehengrundgelenkes.

OBJECTIVE: The objective of this technique is the treatment a severe hallux rigidus deformity by reorientation of an elevated first metatarsal using arthrodesis of the first tarsometatarsal joint and performing a one-step transplantation of an osteochondral graft, which is harvested from the first cuneiform, to the head of the first metatarsal bone. INDICATIONS: Severe arthritis of the first metatarsophalangeal joint (MTP) stage 3 and 4 in the Vanore classification. CONTRAINDICATIONS: General contraindications for a foot surgery; ankylosis of MTP joint; severe arthritis of the sesamoid joint; osteonecrosis; short first metatarsal; previous infection in the metatarsophalangeal joint; large cysts at the head of the first metatarsal. SURGICAL TECHNIQUE: The first step is the preparation of the metatarsophalangeal and the first tarsometatarsal joint. After mobilizing the first metatarsal in a medioplantar direction, a cartilage-bone cylinder is removed from the articular surface of the medial cuneiform using special osteochondral autograft transfer system (OATS) instruments (Small Joint OATS, Arthrex medical instruments GmbH, Munich, Germany). This is followed by the arthrodesis of the first tarsometatarsal joint with reorientation of the position of the first metatarsal bone. Then the removed osteochondral cylinder is implanted into the articular surface of the first metatarsal head. After that the capsule is closed and the skin sutured. POSTOPERATIVE MANAGEMENT: Postoperative management is guided mainly by the requirements of the first tarsometatarsal arthrodesis. When a plantar plate is used pain orientated full weightbearing is allowed in a postoperative shoe with a stiffened sole for 6-8 weeks. Physiotherapy is prescribed to exercise the first metatarsophalangeal joint. RESULTS: In the study, 5 patients were treated with the method described in the years 2011-2012 and were followed up for a period of 2 years. All of these patients were subjectively satisfied with the outcome of the operation. There were no relevant surgery-associated complications.

Comparison of Ligament-Repair Techniques for the Syndesmosis: A Simulated Cadaveric Weight-Bearing Computed Tomography Analysis.

Although the literature describes a variety of reconstructive techniques for the syndesmosis, only few studies offer comparative data. Therefore, the authors compared 2 different ligament repair techniques for the syndesmosis. Sixteen paired fresh-frozen human cadaveric lower limbs were embedded in polymethyl methacrylate mid-calf and placed in a custom-made weightbearing simulation frame. Computed tomography scans of each limb were obtained in a simulated foot-flat loading (75N) and single-leg stance (700N) in 5 different foot positions (previously reported data). One of each pair was then reconstructed via 1 of 2 methods: a free medial Achilles tendon autograft or a long peroneal tendon ligament repair. The specimens were rescanned, compared with their respective intact states and directly with each other. Measurements of fibular diastasis, rotation, anteroposterior translation, mediolateral translation, and fibular shortening were performed on the axial cuts of the computed tomography scans, 1 cm proximal to the roof of the plafond. There was no significant difference in fibular positioning with direct comparison of the reconstructions. Comparisons with their respective intact states, however, showed differences in their abilities to control reduction, most notably in the externally rotated and dorsiflexed positions of the foot. Neither reconstruction was clearly superior in restoring physiologic conditions. Only with a comparison of each technique to its respective intact state were differences between the techniques revealed, a benefit of this particular testing method.

Computed Tomography Analysis for Quantification of Displacement of the Distal Fibula in Different Foot Positions With Weightbearing and Sequentially Increased Instability: An Anatomic Cadaveric Study on Syndesmosis.

Syndesmotic injuries are quite common, but accurate diagnosis and treatment can be difficult, in part because of individual anatomic variation and complex movements of the fibula in the incisura. The current cadaveric study was designed to investigate changes in the position of the fibula in the incisura during simulated weightbearing in different foot positions and with sequential sectioning of syndesmotic and deltoid ligaments. Sixteen paired, fresh-frozen cadaveric limbs were embedded in polymethylmethacrylate mid-calf and placed in a weightbearing simulation frame. Computed tomography scans were obtained while the legs were in a simulated foot-flat position (75 N) and single-leg stance (700 N) in 5 foot positions: neutral, 15° external rotation, 15° internal rotation, 20° dorsiflexion, and 20° plantar flexion. The anterior-inferior tibiofibular ligament, posterior tibiofibular ligament complex, deltoid, and interosseous membranes were sectioned sequentially and rescanned. Measurements of fibular diastasis, rotation, anterior-posterior and medial-lateral translation, and fibular shortening were performed. The most destructive state resulted in the largest displacement at the syndesmosis. The degree of subluxation in all ligament states was dependent on the foot position. External rotation created statistically significant displacement at all levels of injury. There were no significant differences between sides of the same donor. Our data demonstrate the importance of foot position in reduction at the syndesmosis under weightbearing. The current ex vivo model could be used to evaluate other aspects of this injury or the value of reconstructive techniques in the future.

Influence of tibialis posterior muscle activation on foot anatomy under axial loading: A biomechanical CT human cadaveric study.

BACKGROUND: Collapse of the medial longitudinal arch and subluxation of the subtalar joint are common occurrences in adult flatfoot deformity. Controversy exists about the role of the tibialis posterior (TP) tendon as first and/or essential lesion. Subtle changes in the foot configuration can occur under weight bearing. PURPOSE: This human cadaveric study is designed to investigate the effect that isolated actuation of the TP tendon has on the medial longitudinal arch and the hindfoot configuration under simulated weight bearing. METHODS: A radiolucent frame was developed to apply axial loading on cadaveric lower legs during computer tomography (CT) examinations. Eight pairs of fresh-frozen specimens were imaged in neutral position under foot-flat loading (75N) and under single-leg stance weight bearing (700N) without and with addition of 150N pulling force on the TP tendon. Measurements of subtalar joint subluxation, forefoot arch angle and talo-first metatarsal angle were conducted on each set of CT scans. RESULTS: Subtalar subluxation, talo-first metatarsal angle and talo-navicular coverage angle significantly increased under single-leg stance weight bearing, whereas forefoot arch angle significantly decreased. Actuation of the TP tendon under weight bearing did not restore the forefoot arch angle or correct subtalar subluxation and talo-metatarsal angle. CONCLUSION: Significant effect that weight bearing has on the medial longitudinal arch and the subtalar joint configuration is demonstrated in an ex-vivo model. In absence of other medial column derangement, actuation of the TP tendon alone does not seem to reconstitute the integrity of the medial longitudinal arch or correct the hindfoot subluxation under weight bearing. CLINICAL RELEVANCE: The findings of this study together with the developed model for ex-vivo investigation provide a further insight in foot anatomy.

[Fractures of the ankle joint in elderly patients]. / Frakturen des oberen Sprunggelenks beim älteren Patienten.

The number of ankle fractures in elderly patients is increasing. The aim of treatment of ankle fractures in the elderly is to guarantee a possible unlimited autonomy and quality of life for patients. This is achieved by minimization of the complications and impairments after ankle joint fractures. Decisive for the further course is the initial treatment. The results are essentially determined by the soft tissue management, reduction and stable osteosynthesis; however, an orthogeriatric co-management with the implementation of treatment paths and standard operating procedures is recommended. The advantages of an interdisciplinary cooperation of trauma surgeons and geriatricians are obvious in this situation.

Lateral soft-tissue release through a medial incision: Anatomic comparison of two techniques.

BACKGROUND: The distal soft tissue procedure is an integral part of hallux valgus surgery, providing soft tissue balance and alignment restoration of the first metatarsophalangeal joint. Various approaches have been established to this end. For techniques that do not include a separate dorsal incision, lateral release may be achieved via a transarticular approach or via a medial incision and a dorsal flap over the first metatarsal. Compared to the double-incision technique, these techniques are not only cosmetically superior and thus meet the demands of most surgeons and patients. MATERIAL AND METHODS: Using six pairs of frozen cadaveric feet, lateral release was performed using one of the above techniques in a randomized manner with pair comparison. The specimens were then dissected and the completeness of the release as well as any damage to anatomic structures was documented. RESULTS: The transarticular technique enabled complete release of the metatarsal-sesamoid suspensory ligament (MSL) and the transverse and oblique head of the adductor hallucis muscle in five of six specimens. The comparative technique enabled the same in only two of six cases for the adductor hallucis muscle and in four cases for the MSL. The transarticular approach achieved complete release of the lateral joint capsule in three of six specimens, whereas the dorsal approach achieved no release in any specimen. Neither of the methods caused any macroscopic injury to the surfaces of the first metatarsophalangeal joint. The examined arteries, veins, and nerves remained intact in all specimens treated with the transarticular approach, but dorsal release resulted in one documented injury to the first dorsal metatarsal artery and its concomitant veins. CONCLUSIONS: Compared to release by dissection superficially to the extensor tendons, transarticular release provides a more complete lateral release and less injuries to neurovascular bundles. Further anatomic and clinical studies are needed, however, before conclusive recommendations can be made.

First Tarsometatarsal Arthrodesis: An Anatomic Evaluation of Dorsomedial Versus Plantar Plating.

Fusion of the first tarsometatarsal joint is a widely used procedure for the correction of hallux valgus deformity. Although dorsomedial H-shaped plating systems are being increasingly used, fusion can also be achieved by plantar plating. The goal of the present study was to compare these 2 operative techniques based on the anatomic considerations and show the potential pitfalls of both procedures. Six pairs of deep-frozen human lower legs were used in the present cadaveric study. In a randomized manner, either dorsomedial arthrodesis or plantar plating through a medial incision was performed. With regard to arterial injury, the plantar technique resulted in fewer lesions (plantar, 4 injuries [66.7%] to the terminal branches of the first digital branch of the medial plantar artery; dorsomedial, 3 injuries [50%] to the main trunks of the plantar metatarsal arteries and the first dorsal metatarsal artery). With respect to injury to the veins, the plantar procedure affected significantly fewer high-caliber subcutaneous trunk veins. The nerves coursing through the operative field, such as the saphenous and superficial fibular nerves, were compromised more often by the dorsal approach. Neither the plantar plating nor the dorsomedial plating technique was associated with injury to the insertion of the tibialis anterior muscle. Both studied techniques are safe, well-established procedures. Arthrodesis with plantar plating, however, offers additional advantages and is a reliable tool in the foot and ankle surgeon's repertoire.

Lapidus arthrodesis plus osteochondral autograft transplantation in the management of hallux rigidus with an elevated first ray.

The range of joint-sparing treatments for advanced hallux rigidus is still very limited. The authors describe an osteochondral autograft transplantation technique combined with Lapidus arthrodesis as a novel method of obtaining a relatively symptom-free first metatarsophalangeal joint function in patients with hallux rigidus and first-ray elevation.

Modified Lapidus arthrodesis with plantar plate and compression screw for treatment of hallux valgus with hypermobility of the first ray: a preliminary report.

BACKGROUND: TMT-1 arthrodesis is an established method in hallux valgus surgery, but it is technically demanding and typically calls for a period of postoperative immobilization. METHODS: In this cohort study, initial experience with a plantar plate is described. 58 patients (59 arthrodesis) were included. RESULTS: The mean duration of protected full weight bearing was 7 weeks. 94.12% patients were satisfied with the results, bony union was achieved in 98.31%. The Foot Function Index improved by 33 to a mean of 8 (p<.001). The postoperative Mayo Clinic Forefoot Score was excellent in 47.04 and good in 47.04%. The mean hallux valgus angle improved by 24.4-13.2° (p<.001). The mean first intermetatarsal angle improved by 11.2-5.2° (p<.001). CONCLUSION: Initial experience with this form of fixation appears to provide suitable stability, allow early-protected weight bearing, with an acceptable level of complications.

Plantar versus dorsomedial locked plating for Lapidus arthrodesis: a biomechanical comparison.

BACKGROUND: Lapidus arthrodesis with a plate and a compression screw is an established procedure in hallux valgus surgery. The present study was performed to investigate the potential benefit of a compression screw combined with a plantarly applied angle-stable, anatomically precontoured plate or a dorsomedially applied angle-stable plate. METHODS: In six pairs of human cadaver specimens, one specimen each was randomized to receive a dorsomedial H-shaped plate, while the other received a plantar plate. Bone mineral density was measured with peripheral quantitative computed tomography. The specimens were loaded quasi-statically, followed by cyclic loading. Finally, they were loaded to failure. In the static tests, stiffness and range of motion (ROM) data were obtained. In the cyclic tests, the constructs' displacement was studied. In the load-to-failure test, stiffness and maximum load to failure were measured. RESULTS: The two groups did not differ significantly with regard to BMD (p = 0.25). Any significant differences observed were in favor of the plantar constructs, which had greater initial stiffness (p = 0.028) and final stiffness (p = 0.042), a smaller ROM (p = 0.028), and a greater load to failure (p = 0.043). There was no significant difference regarding displacement (p = 0.14). CONCLUSION: In the static tests, the plantar angle-stable plate construct was superior to the dorsomedial angle-stable plate construct. CLINICAL RELEVANCE: Plantar plating appears to offer biomechanical benefit. Clinical studies will be required to show whether this translates into earlier resumption of weightbearing and into lower rates of nonunion.

Notch controls embryonic Schwann cell differentiation, postnatal myelination and adult plasticity.

Notch signaling is central to vertebrate development, and analysis of Notch has provided important insights into pathogenetic mechanisms in the CNS and many other tissues. However, surprisingly little is known about the role of Notch in the development and pathology of Schwann cells and peripheral nerves. Using transgenic mice and cell cultures, we found that Notch has complex and extensive regulatory functions in Schwann cells. Notch promoted the generation of Schwann cells from Schwann cell precursors and regulated the size of the Schwann cell pool by controlling proliferation. Notch inhibited myelination, establishing that myelination is subject to negative transcriptional regulation that opposes forward drives such as Krox20. Notably, in the adult, Notch dysregulation resulted in demyelination; this finding identifies a signaling pathway that induces myelin breakdown in vivo. These findings are relevant for understanding the molecular mechanisms that control Schwann cell plasticity and underlie nerve pathology, including demyelinating neuropathies and tumorigenesis.