[Elbow prosthesis after acute fractures : Indications and technique]. / Ellenbogenprothese nach akuten Frakturen : Indikation und Technik.

Good to very good clinical results can be achieved in older patients with the implantation of a total elbow prosthesis in cases of distal humeral fractures by taking the morphological features of the fractures, the bone quality as well as the individual patient requirements and variables into account. The most commonly used design is the cemented semiconstrained linked total elbow endoprosthesis. The unlinked prosthesis design and hemiarthroplasty require intact or adequately reconstructable musculoligamentous structures or condyles and a preserved or replaced radial head. The recommended weight limit after total elbow prosthesis as well as potential intraoperative and postoperative complications must be considered and discussed with the patients. A secondary total elbow arthroplasty is also possible after primary conservative treatment approaches, e.g., in the case of contraindicated surgery in the fracture situation, persistent pain and functional restrictions. This article provides an overview of the technique and the appropriate indications.

[Mid- to long-term functional results after Bowers' hemiresection interposition arthroplasty of the distal radio-ulnar joint]. / Mittel- bis langfristige, funktionelle Ergebnisse nach Hemiresektion-Interpositions-Arthroplastik (nach Bowers) des distalen Radioulnargelenks.

BACKGROUND: Bowers' hemiresection interposition arthroplasty of the distal radio-ulnar joint has been performed for decades, mainly for the treatment of osteoarthritis of the distal radio-ulnar joint. However, long-term test results are sparse. OBJECTIVE: Evaluation of a homogeneous patient population following a mid- to long-term postoperative follow-up interval after hemiresection interposition arthroplasty. PATIENTS AND METHODS: Twenty-five patients were evaluated 77.2 (±34.6) months after surgical therapy with regard to range of motion, grip strength and pain level. The subjective and objective scores DASH (Disabilities of Arm, Shoulder, and Hand) and MMWS (modified Mayo Wrist Score) were collected. RESULTS: Wrist mobility is not worse than 10.4° in relation to all directions of wrist movement compared with the healthy opposite side. Coarse grip strength is reduced by an average of 5.8 kg compared with the opposite side. The pain level decreased on average from 8.2 preoperatively to 1.8 postoperatively. Postoperatively, 22 patients (88 %) had a stable distal radio-ulnar joint. At the time of follow-up DASH averaged 26.7 (±21.4) and the MMWS averaged 78 (±15.7). DISCUSSION: Hemiresection interposition arthroplasty is a reliable and safe surgical technique with good subjective and functional outcomes in the mid- to long-term.

Anatomic evaluation of the triceps tendon insertion at the proximal olecranon regarding placement of fracture fixation devices.

PURPOSE: Olecranon fractures, especially with a small proximal fragment, remain a surgical challenge. Soft tissue irritation and affection of the triceps muscle bear a risk of complications. In order to find an area for a soft-tissue sparing placement of implants in the treatment of olecranon fractures, we aimed to define and measure the segments of the proximal olecranon and evaluate them regarding possible plate placement. METHODS: We investigated 82 elbow joints. Ethical approval was obtained from the local ethics committee, After positioning in an arm holder and a posterior approach we described the morphology of the triceps footprint, evaluated and measured the surface area of the triceps and posterior capsule and correlated the results to easily measurable anatomical landmarks. RESULTS: We found a bipartite insertional footprint with a superficial tendinous triceps insertion of 218.2 mm2 (± 41.2, range 124.7-343.2), a capsular insertion of 159.3 mm2 (± 30.2, range 99.0-232.1) and a deep, muscular triceps insertion area of 138.1 mm2 (± 30.2, range 79.9-227.5). Olecranon height was 26.7 mm (± 2.3, range 20.5-32.2), and olecranon width was 25.3 mm (± 2.4, range 20.9-30.4). Average correlation between the size of the deep insertion and ulnar (r = 0.314) and radial length (r = 0.298) was obtained. CONCLUSIONS: We demonstrated the bipartite morphology of the distal triceps footprint and that the deep muscular triceps insertion area by its measured size could be a possible site for the placement of fracture fixations devices. The size correlates with ulnar and radial length.

Metacarpal fractures - A method to simulate life-like fractures in human cadaveric specimens for surgical education.

Metacarpal fractures are a type of fracture which trauma surgeons face frequently. Restoration of hand function is the primary objective. The aim of this study was to investigate whether life-like fractures of human cadaveric metacarpals with intact soft-tissue envelope could be simulated for surgical education. Six fresh-frozen human distal forearm and hand specimens were fractured on a custom-made drop-test bench. This reproducible method is based on a weight falling from a predefined height onto the fixed specimens. All fractures were analyzed by fluoroscopy and CT. In all specimens included in this study, several typical lesions were created, resulting in a total of 19 metacarpal fractures. There were 6 fractures involving the capital region, 5 metaphyseal fractures with partial involvement of the diaphysis and 7 pure diaphyseal fractures. One metacarpal comprised a trifocal lesion consisting of a metaphyseal undisplaced fracture, a diaphyseal wedge fracture and a non-displaced articular base fracture. Human cadaveric metacarpals with intact soft tissue can be successfully fractured by a drop-test bench setup. The resulting fractures resemble realistic fracture patterns. Load and exact load angle seem to be critical. Such fractured specimens can be used in surgical education courses. Courses providing fractured specimens with intact soft-tissue envelope can improve clinical teaching for young surgeons and experts alike.

[Minimally invasive procedures in the early stages of trapeziometacarpal joint osteoarthritis : Denervation, arthroscopy and autologous fat transplantation]. / Minimal-invasive Verfahren im Frühstadium der Daumensattelgelenksarthrose : Denervierung, Arthroskopie, autologe Fetttransplantation.

BACKGROUND: Resection arthroplasty of the trapezium with or without tendon interposition is the standard procedure in the treatment of advanced, symptomatic thumb carpometacarpal joint osteoarthritis. Treatment recommendation in the early stages without visible or minimal radiographic changes is often difficult, especially when conservative treatment methods have already been exhausted. In these cases, there is the possibility of the minimally invasive methods of denervation, arthroscopic procedures and autologous fat transplantation. OBJECTIVES: Which minimally invasive procedures are available for the treatment of thumb carpometacarpal joint osteoarthritis and how is their value to be assessed? METHODS: The minimally invasive methods of denervation, arthroscopic procedures and autologous fat transplantation for the treatment of thumb carpometacarpal joint osteoarthritis are described and current results from the literature are discussed. RESULTS: Good results have been reported with all three procedures. However, the reports are almost exclusively based on retrospective studies with small numbers of patients, which lack control groups, so the results cannot be regarded as definitive. CONCLUSIONS: Denervation, arthroscopic procedures and autologous fat transplantation appear to be suitable methods in the early stages of thumb carpometacarpal joint osteoarthritis. Further studies, especially comparative randomised trials that report medium and long-term results, would allow further assessment of these methods.

Long-term outcome after arthroscopic debridement of Palmer type 2C central degenerative lesions of the triangular fibrocartilage complex.

PURPOSE: The purpose of this study was to report long-term objective and patient-reported outcome after arthroscopic debridement of central degenerative triangular fibrocartilage complex (TFCC) lesions. METHODS: A total of 17 patients with central degenerative TFCC (Palmer type 2C) lesions and ulnar positive variance who were treated by arthroscopic debridement were retrospectively reviewed. Mean follow-up was 8.8 years. Assessment facilitating the Modified Mayo Wrist score (MMWS), the Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH score), recording of pain level and of patient satisfaction, and radiological examination were done. RESULTS: Patients reached a pain level of 1.7 VAS, MMW score of 92, and DASH score of 22. No significant differences could be detected between the operated and the contralateral extremity regarding range of motion and grip strength for all patients. No perioperative complications occurred. CONCLUSION: Arthroscopic debridement of central degenerative TFCC lesions is safe, reliable, and efficacious even for ulnar positive variance. LEVEL OF EVIDENCE: Therapeutic IV.

Viscoelastic properties of the human A2 finger pulley.

INTRODUCTION: Biomechanical evaluation of the viscoelastic properties tissue deformation, stiffness, and maximum breaking load of the human A2 pulley. We hypothesized that the A2 pulleys of index, middle, and ring fingers exhibit no difference regarding the aforementioned biomechanical parameters. METHODS: Forty-one A2 pulleys of 14 upper extremities (8 body donors) were assessed. Cyclic and load-to-failure testing were performed. The biomechanical parameters tissue deformation during cyclic and load-to-failure testing, stiffness, and maximum breaking load were determined. RESULTS: No significant differences between the fingers could be detected regarding the biomechanical parameters. A significant negative correlation could be detected between stiffness and deformation of the pulley. Significant positive correlations could be identified between stiffness and maximum breaking load and between maximum breaking load and deformation of the pulleys. CONCLUSIONS: Assessment of the viscoelastic properties of the A2 finger pulley promotes precise diagnosis of pulley lesions and will help to optimize treatment.

Inducing pilon fractures in human cadaveric specimens depending on the injury mechanism: a fracture simulation.

BACKGROUND: Operative management of pilon fractures, especially high-energy compression injuries, is a challenge. Operative education is of vital importance to handle these entities. Not rarely, it is cut by economics and staff shortage. As public awareness toward operative competence rises, surgical cadaver courses that provide pre-fractured specimens can improve realism of teaching scenarios. The aim of this study is to introduce a realistic pilon fracture simulation setup regarding the injury mechanism. MATERIALS AND METHODS: 8 cadaveric specimens (two left, six right) were fixed onto a custom drop-test bench in dorsiflexion (20°) and light supination (10°). The proximal part of the lower leg was potted, and the specimen was exposed to a high energetic impulse via an axial impactor. CT imaging was performed after fracture simulation to detect the exact fracture patterns and to classify the achieved fractures by two independent trauma surgeons. (AO/OTA recommendations and the Rüedi/Allgöwer). RESULTS: All cadaveric specimens could be successfully fractured: 6 (75%) were identified as a 43-C fracture and 2 (25%) as 43-B fracture type. Regardless of the identical mechanism two different kinds of fracture types were reported. In five cases (62.5%), the fibula was also fractured and in three specimens, a talus fracture was described. There was no statistically significant correlation found regarding Hounsfield Units (HU) and age as well as HU and required kinetic energy. CONCLUSION: A high energetic axial impulse on a fixed ankle specimen in light dorsiflexion (20°) and supination (10°) induced by a custom-made drop-test bench can successfully simulate realistic pilon fractures in cadaveric specimens with intact soft tissue envelope. Although six out of eight fractures (75%) were classified as a 43-C fracture and despite putting a lot of effort into the mechanical setup, we could not achieve an absolute level of precision. Therefore, we suggest that the injury mechanism is most likely a combination of axial loading, shear and rotation. LEVEL OF EVIDENCE: III.

Overlengthening of the radial column in radial head replacement: a review of the literature and presentation of a classification system.

BACKGROUND: Radial head arthroplasty is a common procedure in elbow surgery. It has been shown to be of benefit for the patients, but there also are relevant complications that should be prevented if possible. One significant complication is overlengthening of the radial head prosthesis. In overlengthening, the head of the prosthesis overextends the physiological level of the native radial head and leads to overcompression in the radiohumeral joint. Rapid erosion and arthritic changes may then impede the clinical outcome. The incidence of overlengthening is not precisely known, but estimations range to up to 20% of all implanted prostheses. METHODS: The present review discusses the available body of literature on overlengthening and lines out a classification system that may be used to guide treatment algorithms. The classification is based on the personal experiences of the author during their clinical practice. RESULTS: In low-grade overlengthening (type I) conservative treatment can be an option. In Types II-IV usually revision surgery is needed. Depending on the state of the capitulum and joint stability, it is possible re-implant a prosthesis, or rely on implant removal alone. DISCUSSION: The present review aimed at shedding light into overlengthening as a complication radial head replacement and to help identify and treat it.

[External fixator of the elbow]. / Fixateur externe am Ellenbogen.

AIM OF SURGERY: The placement of an external elbow fixator can be statically carried out as temporary stabilization or as a hinged movement fixator. As a hinged movement fixator a functional follow-up treatment is possible due to control of the joint guidance and reduction of the compromising forces on the osteoligamentous structures. INDICATIONS: As a temporary stabilization of the elbow, the external fixator is used as a damage control method. As a movement fixator it is used as an additional protection and movement control after complex osteoligamentous interventions and persisting tendency to dislocation of the joint and also as a standalone procedure. In some cases, the procedure is also used in distraction arthrolysis of stiff elbows and as a salvage procedure in patients with relevant comorbidities as part of fracture treatment. CONTRAINDICATIONS: Inexperience in relation to the procedure as well as a local acute infection at the level of the intended pin locations should specifically be mentioned as contraindications. In addition, compliance and patient understanding of the procedure are essential for the success of treatment. SURGICAL TECHNIQUE: Soft tissue preparation for pin placement should be preferred over percutaneous incisions to enable a safe bone exposure. Knowledge of the course of neurovascular structures (particularly the radial nerve) is essential. When placing a hinge, knowledge of the position and detection of the idealized center of rotation is of fundamental importance. POSTOPERATIVE MANAGEMENT: The type of postoperative management required essentially depends on the underlying injury. When placing a hinged fixator, the aim is to enable movement as early as possible. Nevertheless, blocking of the hinged fixator may be useful for a short period of time. Adequate pin care over the duration of the treatment is essential in order to prevent complications. RESULTS: Good functional results have been reported for the treatment of unstable elbows after primary and secondary placement of a hinged external fixator. Good functional scores and improvement in the range of motion were also recorded in the context of an arthrolysis (additive for open arthrolysis or distraction arthrolysis); however, in contrast a significant number of complications associated with this surgery are likely to emerge. As a definitive salvage procedure, satisfactory results were obtained in a small case series of a selected older patient group with relevant comorbidities.

[Revision surgery after failed (partial-) arthrodesis of the wrist]. / Revisionen nach fehlgeschlagenen (Teil­)Versteifungen am Handgelenk.

(Partial) arthrodeses of the wrist have been proven cornerstones to treat many lesions for decades, especially in the case of revision surgery. Four-corner, scapho-trapezo-trapezoidal (STT), radio-scapho-lunate (RSL) and total wrist fusions are very common techniques in hand surgery. However, even these proven surgical procedures have significant non-fusion rates. Prior to revising a failed arthrodesis, it is essential to analyse the latter failure precisely. A technically adequate revision is only feasible when based on a correct and meticulous analysis. The understanding of the biological processes and technical aspects of the implants are the basis for solving this issue.

[Tenolysis of extensor and flexor tendons of the hand]. / Tenolyse von Streck- und Beugesehnen an der Hand.

BACKGROUND: Unrestricted gliding of extensor and flexor tendons is essential for normal functioning of the hand. If tendon gliding is impaired, a restricted range of motion of finger joints and, finally, joint stiffness result. OBJECTIVES: To answer the questions about the causes of tenodesis in the hand, which examinations are most informative, how tenolysis is technically performed, and what results can be expected. METHODS: The reasons, examinations, surgical technique, and results of extensor and flexor tendon tenolysis are presented. RESULTS: Based on the data in the literature tenolysis of flexor tendons leads to range of motion that is only 50-60% of the preoperative range of motion. In about 20% of patients, deterioration as serious as secondary tendon rupture is observed. Meaningful results of extensor tendon tenolysis have not yet been published. CONCLUSIONS: Tenolysis of extensor and flexor tendons in the hand is a demanding surgical procedure, and in addition to detailed knowledge of anatomy and biomechanics, it requires sufficient experience-especially following the primary repair of tendon injuries. The earliest indication for tenolysis can occur at about 3 months, usually after 6 months, if continuous intensive hand therapy and splinting have not been successful. General and individual benefits and risks must be carefully weighed. The key to successful tenolysis is the patient's access to and unrestricted participation in competent postoperative treatment, ideally performed by a specialist in hand therapy, which may last for weeks or months.

[Surgical treatment of carpal tunnel syndrome: open release of the flexor retinaculum and hypothenar fat flap for revision surgery]. / Operative Behandlung des Karpaltunnelsyndroms: offene Retinakulumspaltung und Hypothenarfettlappenplastik beim Rezidiv.

OBJECTIVE: Decompression of the median nerve by complete release of the flexor retinaculum and the distal antebrachial fascia. In the case of revision surgery providing of a scar-free covering of the median nerve, if necessary. INDICATIONS: Carpal tunnel release is indicated for symptomatic patients with painful paraesthesia or neurological deficits after adequate diagnostic evaluation. The hypothenar fat flap is indicated in revision surgery if a sufficient nerve bed of the median nerve is needed and to restore nerve gliding. CONTRAINDICATIONS: General operative limitations. The hypothenar fat flap is not indicated in revision surgery if median nerve irritation is not caused by surrounding scaring but other reasons like tendonitis. SURGICAL TECHNIQUE: Proximal longitudinal incision of the palm. Subcutaneous dissection and incision of the palmar aponeurosis. Careful ulnar incision of the transverse carpal ligament. Considerate release of the distal and proximal parts of the retinaculum as well as the distal part of the antebrachial fascia. Exploration of the median nerve and palpation of the carpal tunnel and resection of compressive structures, if necessary. In case of revision surgery, if required, the hypothenar fat flap is raised. The fat flap is transposed without tension palmar to the median nerve and fixed to the radial side of the carpal tunnel. POSTOPERATIVE MANAGEMENT: Early functional mobilization. Immobilization for a short period is optional. After revision surgery and hypothenar fat flap, splinting for one week is recommended.

[Surgical approaches to the hand]. / Operative Zugangswege an der Hand.

OBJECTIVE: Accessibility of any anatomical structure of the hand via surgical approach. INDICATIONS: Any surgical treatment of the hand. CONTRAINDICATIONS: Any contraindication to surgical treatment of the hand. SURGICAL TECHNIQUE: Skin incision at the hand with access to any anatomical structure. POSTOPERATIVE MANAGEMENT: Postoperative treatment depends on the disease and hand surgery performed.

Peroneal nerve location at the fibular head: an anatomic study using 3D imaging.

INTRODUCTION: Injuries to the peroneal nerve are a common complication in operative treatment of proximal tibial or fibular fractures. To minimize the risk of iatrogenic injury to the nerve, detailed knowledge of the anatomy of the peroneal nerve is essential. Aim of this study was to present a detailed description of the position and branching of the peroneal nerve based on 3D-images to assist preparation for surgical approaches to the fibular head and the tibial plateau. METHODS: The common peroneal nerve, the deep and the superficial peroneal nerve were marked with a radiopaque thread in 18 formalin-embalmed specimens. Three-dimensional X-ray scans were then acquired from the knee and the proximal lower leg in full extension of the knee. In 3D-reconstructions of these scans, distances of the common peroneal nerve and its branches to clearly defined osseous landmarks were measured digitally. Furthermore, the height of the branching of the common peroneal nerve was measured in relation to the landmarks. RESULTS: The mean distance of the common peroneal nerve at the level of the tibial plateau to its posterior osseous limitation was 7.92 ± 2.42 mm, and 1.31 ± 2.63 mm to the lateral osseous limitation of the tibia. In a transversal plane, distance of the common peroneal nerve branching was 27.56 ± 3.98 mm relative to the level of the most proximal osseous extension of fibula and 11.77 ± 6.1 mm relative to the proximal extension of the tibial tuberosity. The deep peroneal nerve crossed the midline of the fibular shaft at a distance of 22.14 mm ± 4.35 distally to the most proximal extension of the fibula, the superficial peroneal nerve at a distance of 33.56 mm ± 6.68. CONCLUSION: As the course of the peroneal nerve is highly variable in between individuals, surgical dissection for operative treatment of proximal posterolateral tibial or fibular fractures has to be done carefully. We defined an area were the peroneal nerve and its branches are unlikely to be found. However, specific safe zones should not be utilized due to the individual anatomic variation.

Pronator quadratus repair with a part of the brachioradialis muscle insertion in volar plate fixation of distal radius fractures: a prospective randomised trial.

INTRODUCTION: Stable pronator quadratus repair following volar plate fixation of distal radius fractures with complete plate coverage is difficult. MATERIALS AND METHODS: This study compares a modified pronator quadratus repair technique involving the brachioradialis muscle insertion (test group) with a conventional radial incision through the muscle without pronator quadratus repair (standard group). This prospective randomised study included 16 patients in the test group and 12 in the standard group; all were available for clinical, radiographic and ultrasound examination at a mean follow-up of 15 months. RESULTS: Pronator quadratus repair was feasible in all test group patients, and complete coverage of the distal plate was achieved in 11. No differences in functional outcome were observed between the groups. CONCLUSION: Pronator quadratus repair with a part of the brachioradialis muscle insertion is a reliable technique for coverage of a volar plate by slight distal transposition. In the repair of distal radius fractures, this may better protect the finger flexor tendons against irritation and/or rupture. That likelihood should now be studied.

Correction to: Insertion of the Ascension PyroCarbon PIP total joint in 152 human cadaver fingers: analysis of implant positions and malpositions.

In the experimental study the distal component of the Ascension PyroCarbon proximal interphalangeal total joint prosthesis was implanted 180° rotated. Figures 2-5 show the implant malpositions. The methods, results, and conclusion of the study were not affected by this.

[Total elbow arthroplasty in traumatic and post-traumatic bone defects]. / Ellenbogentotalendoprothetik bei traumatischen und posttraumatischen Knochendefekten.

Total elbow arthroplasty is currently most commonly carried out due to acute trauma or post-traumatic conditions. Bone defects are often present and must be considered in the (pre-)operative workup. The use of semi-constrained prostheses with a systematic cementing technique through a triceps-on approach leads to satisfying clinical results, however, the outcome is worse when compared with rheumatic patients.Primary total elbow arthroplasty for complex distal humerus fractures in the elderly patient or secondary implantation following failed conservative treatment or osteosynthesis represent possible indications for (post­)traumatic joint replacement. The condyles do not have to be reconstructed and the humerus can be shortened by 2-3 cm without sacrificing the functionality of the extensor apparatus. In the case of post-traumatic joint destruction and pronounced chronic instability following complex fractures of the proximal forearm - especially following terrible triad or Monteggia-like injuries - total elbow arthroplasty can be considered as a treatment option. The extensor apparatus must be reconstructed, and the implantation of the prosthesis must thus be combined with plate osteosynthesis of the ulna - if necessary. Chronic deformity should only be corrected as much as needed in order to avoid early aseptic loosening due to increased shearing forces and polyethylene wear.Massive bone loss is problematic and can be compensated with allografts or tumor prostheses. The results of these salvage procedures are less predictable, and complication rates increase significantly.

Accuracy of 3D fluoro-navigated anterior transpedicular screws in the subaxial cervical spine: an experimental study on human specimens.

INTRODUCTION: Pedicle screw stabilization, the standard technique in the thoracic and lumbar spine, is increasingly used in the cervical spine. Initial studies on the use of anterior pedicle screws (ATPS) in the cervical spine have been recently published. ATPS use has theoretical advantages over posterior stabilization. We have already established a 3D-fluoroscopy navigation setup in a study of artificial bones. The aim of the current study was to evaluate the positioning quality/accuracy of ATPS introduced to human specimens. METHODS: 36 cannulated screws (3.5 mm) were implanted anteriorly into the C3-C7 segments of four spines (unfixed, frozen, cadaveric specimens) using a 3D-fluoroscopy navigation system. Placement accuracy was evaluated using a recently published classification on postoperative CT scans. Grade 1 is perfect position with pedicle wall perforation <1 mm, grade 2 is perforation <2 mm, etc., and finally grade 5 is cortical perforation of >4 mm and/or transverse foramen entry. RESULTS: 36 anterior pedicle screws were inserted into four human cervical spine specimens. Of these, seven screws were introduced to C3, five to C4 and eight each to C5, C6, and C7. Classified with the modified G&R, 21 of 36 (58.3%) were grade 1. Ten screws (27.8%) were grade 2. Grade 4 was assessed for two screws and grade 5 for three. Customary "good" positioning, combining grades 1 and 2, was thus found in 86.1%. Five screws (13.9%) did not meet this criterion (grade ≥3). CONCLUSIONS: With 86.1% of good positioning (grade 2 or better), a 3D-fluoroscopy navigation of ATPS screws into human c-spine specimens achieved a satisfying results. These are at least comparable to results presented in the literature for posteriorly introduced subaxial pedicle screws.

[Cubital tunnel syndrome : Diagnostics and therapy]. / Kubitaltunnelsyndrom : Diagnostik und Therapie.

Cubital tunnel syndrome is the second most common nerve compression syndrome observed in the upper extremity. Mechanical irritation of the ulnar nerve is also found in the upper and the lower arm even though cubital tunnel syndrome is documented most of the time. Apart from clinical examination electrophysiological testing is the most important contributor to the therapy decision. Depending on the clinical manifestation conservative treatment with elbow splinting may be appropriate. In the event of persistent or advanced nerve irritation surgical decompression may be the sensible intervention. Open or endoscopically assisted in situ decompression is currently recommended as the primary intervention while anterior transposition of the ulnar nerve is recommended for revision surgery.