A lateral fracture step-off of 2mm increases intra-articular pressure following tibial plateau fracture.

INTRODUCTION: The aim of this study was to evaluate the effects of increasing posttraumatic step-offs after lateral tibial plateau fracture reduction on the intra-articular pressure. MATERIALS AND METHODS: In eight fresh-frozen human cadaveric knees with intact menisci, a standardized sagittal osteotomy of the lateral tibial condyle was performed as an OTA/AO type 41-B1 fracture-model. The fragment was fixed by a customized sled including an angular stable tibia plate to evaluate step-offs from 0 mm to 8 mm in 1mm increments. In a servo-hydraulic testing machine, an axial force was applied to the tibial plateau in 0° (700N), 15° (700N), 30° (700N), 60° (350N), and 90 ° (350N) of flexion while the joint pressure was recorded by two pressure sensors. RESULTS: A 1mm step-off did not result in an increased joint pressure. At 60° of flexion a 2mm step-off increased the lateral joint pressure by 61.84kPa (P = 0.0027). In 30° of flexion, a 3mm step raised the lateral joint pressure by 66.80kPa (p = 0.0017), whereas in 0°, 15° and 90° of flexion, a 4mm step increased the pressure by >50kPa (P < 0.05). Concomitant medial joint pressure increments were lower than those in the lateral plateau. A significant increase of 19-24kPa in the medial joint pressure was detected in 90° of flexion with a 1mm lateral step (P = 0.0075), in 15° and 60° of flexion with a 2mm step (P < 0.05), in 0° of flexion with a 4mm step (P = 0.0215) and in 30° of flexion with a 7mm step (P = 0.0487). CONCLUSION: Lateral fracture step-offs of 2mm or larger should be reduced intraoperatively to avoid large increases in lateral joint pressure.

[Dorsal plate arthrodesis of the thumb metacarpophalangeal joint]. / Die Arthrodese des Daumengrundgelenks durch Plattenosteosynthese.

OBJECTIVE: Elimination of pain or instability by arthrodesis of the thumb joint in functional position by dorsal plateosteosynthesis. INDICATIONS: Painful primary or secondary arthrosis of the thumb, nonreconstructable ulnar, radial or palmar instability, posttraumatic dislocation, defect injuries, bone tumors in the region of the thumb metacarpophalangeal joint. CONTRAINDICATIONS: Local infection of the thumb metacarpophalangeal joint area. SURGICAL TECHNIQUE: Dorsal approach to the thumb metacarpophalangeal (MP) joint, splitting of the extensor aponeurosis between the extensor pollicis longus and extensor pollicis brevis tendon. Opening of the anterior capsule and separation of the collateral ligaments, open up the joint, narrow concave and convex joint surface resections, adjustment of the arthrodesis position in 10-20° flexion and K­wire transfixation, dorsal plateosteosynthesis, fine adjustment of the flexion, axis and pronation position. Closure of the capsule and the periosteal gliding tissue over the plate, reconstruction of the extensor aponeurosis. POSTOPERATIVE MANAGEMENT: Splint for 3 weeks. Full load after 6-8 weeks. RESULTS: The dorsal plate arthrodesis of the thumb MP joint is a reliable surgical method with very good functional results.

[Anatomy and pathobiomechanics of the scaphoid]. / Anatomie und Pathobiomechanik des Skaphoids.

Among the carpal bones the scaphoid (Os scaphoideum) is the most important. The most frequent fracture of the carpus is a fracture of the scaphoid bone. The frequently occurring absence of healing of these fractures as well as unhealed ruptures of the ligament complex between the scaphoid and lunate, lead to the most severe biomechanical and thus the most severe clinical changes of the wrist. The detailed anatomy of the scaphoid, blood flow, ligament attachments, injury mechanisms and pathobiomechanics are described and illustrated.

[The fibrous skeleton of the hand : Changes with Dupuytren's contracture]. / Das fibröse Skelett der Hand : Veränderungen bei der Dupuytren-Kontraktur.

The exact knowledge of the anatomy of the fibrous skeleton of the hand is an absolute prerequisite for any treatment of Dupuytren's disease. The fibrous skeleton does not only include the palmar aponeurosis, but also numerous retinacula cutis, which are not found in current anatomy books. Here, eponyms facilitate the otherwise difficult and over-pronounced names of the fiber systems. Skoog, Legueu and Juvara, Gosset, Grapow, Grayson, Cleland, Thomine, and Barton are the most important. This systematic review of the fibers and strands is designed to help reduce iatrogenic complications.

[Anatomy and biomechanics of the scaphoid]. / Anatomie und Biomechanik des Kahnbeins.

The scaphoid is biomechanically and clinically of great importance for function of the wrist. In the literature, its anatomy and biomechanics are clearly underrepresented as well as underestimated. In the following review the scaphoid will be presented in more detail, according to recent information and findings. Not only will the origin of the name and the history of previous names, such as cotyloid or navicular, be introduced, but also for the first time in medical literature the significant phylogeny and ontogeny of the scaphoid will be shown. Moreover, the clinically very important blood supply, the ligaments of the scaphoid and relevant biomechanical details will be described.

[Treatment of instability of the metacarpophalangeal and trapeziometacarpal joints of the thumb]. / Behandlung der Instabilität des Daumengrund- und des Daumensattelgelenks.

Restoration of stability of the thumb represents an enormous gain of function for the patient and can be achieved by arthrodesis or ligament reconstruction. Ligament reconstruction should only be performed if good stability and mobility and a pain-free grip can also be achieved. In every case surgery must protect the delicate soft tissues and should be based on a profound knowledge of the anatomical and biomechanical circumstances. Instability of the trapeziometacarpal joint is rare but metacarpophalangeal joint instability (ulnar, palmar and radial) is relatively frequent. For both conditions arthrodesis is the most frequently used and easier surgical procedure. Ligament reconstruction is more difficult to perform but can maintain the mobility of these joints.

[Ligament reconstruction in extensor tendon dislocation]. / Bandplastik bei Strecksehnenluxation über dem Fingergrundgelenk.

OBJECTIVE: Stabile recentering the extensor tendon over the top of the head of the metacarpal to restore the exact tension and the direction. INDICATIONS: Dislocation of the extensor tendon at the metacarpophalangeal (MP) joint with functional disabilities of the fingers. CONTRAINDICATIONS: Severe osteoarthritis of the MP joint. Accompanying injuries of collateral ligaments. Fibrosis of the MP joint or contractures of the intrinsic muscles. SURGICAL TECHNIQUE: Curved 8 cm skin incision at distal metacarpal, MP joint, and proximal phalanx. A distally pedicled central tendon strip from the extensor digitorum communis (EDC) tendon is removed. Centralization of the tendon by reconstructing the sagittal ligament and the proximal part of the extensor hood. The tendon strip is wrapped around the tendon of the interossous muscle. POSTOPERATIVE MANAGEMENT: Immobilization of the MP joint in 30° flexion with free proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints for 4 weeks. Full fist after 5 weeks. RESULTS: In all 16 patients good or very good results were achieved. There were no recurrences of tendon dislocations, no MP joint contractures, and only a few minor extensor tendon adhesions.

[Suture techniques for flexor tendons of the hand]. / Nahttechniken für Beugesehnen der Hand.

BACKGROUND: The success of the flexor tendon suture depends on many factors. An important factor is that the tendon suture technique that must be carried out for flexor tendons is considerably more complex and more precise than for all other tendons of the body. OBJECTIVES: To discover important technical points that need to be considered during flexor tendon suturing. METHOD: We compiled the most important technical details in flexor tendon suturing from the literature and from personal experience. RESULTS: Details on core suture, peripheral suture, the tensile strength, gapping, the circulation of sutured tendons, gliding resistance and excisions are discussed. CONCLUSIONS: Flexor tendon suturing must be performed taking great care to conserve tissue.

[Pulley reconstruction in the hand]. / Ringbandrekonstruktion an der Hand.

BACKGROUND: To ensure proper function of the flexor tendons, pulleys are extremely important. Pulleys can be impaired by injury, infection, but also sometimes iatrogenically. The consequences of this failure are often poorly understood. OBJECTIVES: What is the impact of pulley insufficiency, what are the clinical signs, and what are the reconstruction options? METHODS: The experiences of 64 patients with different forms of pulley insufficiency are presented. RESULTS: All patients benefit from a ring ligament reconstruction. A phalanx fracture can be one complication. CONCLUSIONS: Pulley reconstructions are very beneficial operations.

[Flexor tendon transplantation]. / Beugesehnentransplantation.

BACKGROUND: Insufficiency of both flexor tendons of a finger considerably disrupts the function of the whole hand. Flexor tendon transplantation represents the best way to reconstruct or improv function in many cases. OBJECTIVES: Based on the literature and our own results, not only the current state of the surgical technique, but also the opportunities and dangers of this sophisticated operation, are represented. Knowledge of alternative methods is important. METHODS: With a follow-up of between 2 to 12 years, a total of 272 patients who underwent flexor tendon transplantation in the hand during several periods from 1974 to 2000 were investigated. RESULTS: Similar to the international literature, our long-term results did not specify the exact surgical technique (pedicled or free). According to the Buck-Gramcko score, 32 % had very good results, 26.4 % good, 15.1 % satisfactory, and 26.5 % poor. CONCLUSIONS: Numerous details need to be considered before, during, and after surgery. For the patient, the procedure has tremendous significance in many ways; thus, this operation should only be performed by an experienced hand surgeon.

[Ligament reconstruction for trapeziometacarpal joint instability]. / Bandplastik bei Instabilität des Sattelgelenks.

OBJECTIVE: Restoring stability and preventing subluxation/dislocation of the trapeziometacarpal (first carpometacarpal = CMC-I) joint while preserving mobility. INDICATIONS: Posttraumatic, acquired or congenital instability of the CMC-I joint. CONTRAINDICATIONS: Existence of osteoarthritis of the CMC-I joint. Neurogenic or muscular origin dysfunction of thenar muscles and other contractures the CMC-I area. Infections. SURGICAL TECHNIQUE: Radiopalmar approach to the CMC-I joint, reduction, and transosseous ligament reconstruction with a distally pedicled tendon strip from the abductor pollicis longus muscle. POSTOPERATIVE MANAGEMENT: Splint immobilization for 5 weeks. RESULTS: This procedure generally results in good or very good outcomes. Of 24 patients, only one patient experienced rupture of the ligament reconstruction. Ligament reconstruction for the carpometacarpal joint of the thumb relieves pain and restores stability while preserving functional range of motion in patients with chronic instability.

[Restoration of ulnar collateral ligament stability of the metacarpophalangeal joint of the thumb]. / Ulnare Kollateralbandplastik des Daumengrundgelenks bei chronischer Instabilität.

OBJECTIVE: Restoration of ulnar collateral ligament stability of the metacarpophalangeal (MP) joint of the thumb with elimination of palmar subluxation while retaining mobility for chronic instability without osteoarthritis. INDICATIONS: Acquired or congenital chronic instability of the MP joint of the thumb with compelling reasons for joint preservation and against arthrodesis, e.g., an arthrodesis or arthritis of adjacent joints. CONTRAINDICATIONS: Arthritis of the thumb MP joint. Contractures of the MP joint. Low natural range of motion of the joint (compared to the contralateral hand). Additional palmar instability with significant hyperextensibility. Infections. Lesions to the median and/or ulnar nerve with impaired active mobility. SURGICAL TECHNIQUE: Anatomical reconstruction of the ulnar collateral ligament and the accessory collateral ligament using a tendon graft (palmaris longus tendon). Ulnar approach, transosseous course of the tendon graft and elimination of subluxation. POSTOPERATIVE MANAGEMENT: Splint for 5 weeks and hand therapy. RESULTS: Of 12 patients undergoing this type of ligament reconstruction, all achieved good stability and pain-free range of motion, which was 60-95% of the contralateral hand. This surgical procedure has few complications and is considered reliable.