[Arthroscopy of the distal radioulnar joint]. / Die Arthroskopie des distalen Radioulnargelenks.

OBJECTIVE: The aim of the procedure is to visualize the proximal pouch of the DRUJ, the joint surfaces of the sigmoid notch and the ulnar head, the convexity of the ulnar head and the proximal ulnar side surface of the triangular fibrocartilage complex (TFCC). INDICATIONS: Arthroscopy of the distal radioulnar joint is applied for the evaluation of joint pathologies in ulnar-sided wrist pain, especially in cases without diagnostic findings in standard X­rays and MRIs and arthroscopically assisted procedures. SURGICAL TECHNIQUE: In vertical extension, two portals of the wrist are created on the dorsal side of the DRUJ between the extensor digiti minimi and extensor carpi ulnaris tendons. By insertion of a small joint arthroscope via these portals visualization of the ulnar head, the sigmoid notch, the proximal pouch of the DRUJ and the proximal surface of the TFCC is accomplished. CONCLUSIONS: Arthroscopy of the DRUJ is a rarely and not routinely performed procedure for the diagnosis and therapy of ulnar-sided wrist pain. It is technical demanding with a flat learning curve and anatomy-related obstacles. A complete view of the joint is not always accessible. Rare complications are injuries of the extensor digiti minimi tendon, as well as contusion or sectioning of the transverse branch of the dorsal branch of the ulnar nerve. In distinct cases, this procedure offers important additional information about the distal radioulnar joint. The procedure is especially valuable for the detection of proximal TFCC injuries that are missed otherwise.

[Grip strength measurement : Significance and boundaries]. / Die Messung der Griffkraft : Wertigkeit und Grenzen.

BACKGROUND: Grip strength measurement is a widely used method for clinical as well as scientific purposes. In hand surgery, it is an essential component in the diagnosis of disease, treatment sequences and assessment. In epidemiological studies, it is a good predictor of healthy ageing or disease progression. PROBLEM: Measurement results and their interpretation can be influenced by many factors. The historical development of dynamometry, measurement technology and the standard values in various population groups are presented. Comparisons with standard values should only be made using current tables because the grip strength has changed in recent decades. Assessment of the voluntarily submaximal grip strength remains problematic. Proposals are made for how to assess grip strength during the evaluation.

[Arthrodesis of the trapeziometacarpal joint]. / Die Arthrodese des Daumensattelgelenks.

OBJECTIVE: Bony fusion of the trapeziometacarpal joint. INDICATIONS: High demands concerning stability and strength of the thumb in primary or secondary osteoarthritis (e.g., posttraumatic osteoarthritis following injuries to the carpometacarpal joint of the thumb); instability in the absence of osteoarthritis due to malformations, ligamentous laxicity, and joint hypermobility; malformations; improvement of hand function in neurological disorders; salvage procedure after carpometacarpal arthroplasty provided bone stock is sufficient. CONTRAINDICATIONS: Osteoarthritis or stiffness of adjacent joints, activities demanding maximal mobility of the thumb, insufficient bone stock. SURGICAL TECHNIQUE: Resection of the articular surfaces of the trapeziometacarpal joint via a dorsal approach. After temporary K­wire transfixation, application of a dorsal T­shaped plate (fixed angled or not), replacement of the K­wire with a lag screw. POSTOPERATIVE MANAGEMENT: Immobilization for 8 weeks (radial below-elbow cast including the thumb metacarpophalangeal joint); standard radiographs on second postoperative day and after 8 weeks; removal of stitches after 2 weeks; with bony healing after removal of the cast, guided exercises to increase strength and mobility; full loading for manual tasks after 3 months. RESULTS: With regards to strength, stability, and pain reduction, results are rated as good and excellent with a high degree of patient satisfaction. Disadvantages are implant-related complications and nonhealing of the fusion in an average of 13% of patients. Nevertheless, the procedure is still indicated in young manual workers who tolerate some limitations of mobility.

Diagnosing central lesions of the triangular fibrocartilage as traumatic or degenerative: a review of clinical accuracy.

This study examined the reliability of surgeons' estimations as to whether central lesions of the triangular fibrocartilage complex were traumatic or degenerative. A total of 50 consecutive central triangular fibrocartilage complex lesions were independently rated by ten experienced wrist surgeons viewing high-quality arthroscopy videos. The videos were reassessed after intervals of 3 months; at the second assessment surgeons were given the patient's history, radiographs and both, each in a randomized order. Finally, the surgeons assessed the histories and radiographs without the videos. Kappa statistics revealed fair interrater agreement when the histories were added to the videos. The other four modalities demonstrated moderate agreement, with lower Kappa values for the assessment without videos. Intra-rater reliability showed fair agreement for three surgeons, moderate agreement for two surgeons and substantial agreement for five surgeons. It appears that classification of central triangular fibrocartilage complex lesions depends on the information provided upon viewing the triangular fibrocartilage complex at arthroscopy. LEVEL OF EVIDENCE: II.

[Carpus and distal radioulnar joint : Clinical and radiological examination]. / Carpus und distales Radioulnargelenk : Klinische und röntgenologische Untersuchung.

A precise medical history and specific symptom-oriented clinical tests of the wrist joint should always precede any radiological, computed tomography (CT) or magnetic resonance imaging (MRI) diagnostics. In many cases, specific clinical tests of the wrist joint allow at least a preliminary diagnosis, which can be supported by standard radiography using correct projections. A systematic approach is recommended covering the radiocarpal, midcarpal, ulnocarpal and distal radioulnar joints. Exact identification of the palpable anatomic landmarks is mandatory for correct application and interpretation of the various clinical tests. The results of the clinical tests in combination with radiological imaging can often detect precisely ruptures of distinct wrist joint ligaments and localized arthritis.

[Reconstruction of the Distal Radioulnar Ligaments According to Adams: Surgical Technique - A Video]. / Rekonstruktion der distalen radioulnaren Bänder nach Adams: Operationstechnik - ein Video.

This paper describes the surgical technique to reconstruct the distal radioulnar ligaments using the palmaris longus tendon as inaugurated by Brian Adams. A video can be approach online.

[Aptis Prosthesis for the Treatment of Painful Instability of the Ulnar Stump Following Wide Excision of the Distal ulna]. / Aptis-Prothese bei schmerzhafter Instabilität des Ulnastumpfes nach hoher Resektion der Ulna.

We report the case of 35-year-old woman with severe Madelung's deformity. Having undergone a Kapandji-Sauvé-procedure with wide excision of the distal ulna, the patient suffered from painful instability of the ulnar stump. Although a corrective osteotomy of the distal radius had been performed, severe ulnar inclination of the distal radius remained, leaving persisting pain. Implantation of a constrained distal radioulnar joint prosthesis combined with a renewed extraarticular corrective osteotomy of the distal radius was performed. The peg of the radial plate of the prosthesis was placed in the screw hole of the large-fragment lag screw removed after the Kapandji-Sauvé-procedure.

[Hand injuries in mountain sports]. / Handverletzungen beim Bergsport.

BACKGROUND: Apart from clean cut finger amputations, every kind of hand injury can be seen in mountain and winter sports but only skier's thumb and injuries of the pulley system in sport climbers are seen in a greater number of cases. Nevertheless, these two common injuries as well as the rare frostbite of the fingers are often underdiagnosed or overdiagnosed as well as undertreated or overtreated. PURPOSE: This paper describes the diagnostics and treatment of skier's thumb, injuries of the pulley system in sport climbers and frostbite of the fingers. RESULTS: Before checking the metacarpophalangeal (MP) joint of the thumb for stability, radiographs should be taken to exclude a bony avulsion of the ulnar collateral ligament in skier's thumb. If there is no bony ligament avulsion further diagnostic procedures, e.g. ultrasound, are recommended to prove or exclude a Stener lesion, which is an absolute indication for operative treatment together with a dislocated bony ligament avulsion. To quantify the severity of a lesion of the pulley system ultrasound and magnetic resonance imaging (MRI) are needed. Most lesions of the pulley system can be treated conservatively. Only multiple pulley ruptures or isolated ruptures associated with a lesion of the lumbrical muscles or collateral ligaments require operative treatment. As long as there is no infection amputation should be done as late as possible in frostbite of the fingers because the extent of the frostbite can rarely be correctly estimated. CONCLUSION: Most cases of skier's thumb as well as lesions of the pulley system can be treated non-operatively but precise diagnostics are needed.

[Scapholunate lesions]. / Die skapholunäre Bandverletzung.

Injuries to the scapholunate ligament are the most frequent cause of carpal instability. Therefore, if a scapholunate lesion is not diagnosed, it may result in a severe dysfunction of the wrist. This review describes the anatomy, and the kinematics of the wrist with an intact as well as a disrupted scapholunate ligament. The diagnostic of an isolated ligament lesion and a ligament injury associated with a fracture of the distal radius is presented. Finally, an algorithm for treatment based on the stage of injury is proposed.

[Median nerve neuropathy after perilunate dislocation injuries]. / Neuropathie des N. medianus nach perilunären Luxationsverletzungen.

PURPOSE: The purpose of this retrospective study was to investigate the frequency and appearance of median nerve neuropathy following perilunate dislocation injuries with respect to the preceding surgical decompression and the clinical outcome. PATIENTS AND METHODS: 32 patients were followed for a mean of 65 months after surgery for perilunate dislocation, including carpal tunnel release in 13 patients. 10 of 11 patients with clinical symptoms of median nerve affection at follow-up had additionally an electrophysiological examination. Median neuropathy was assumed if 2 or more parameters were pathologic. Patients with and without median neuropathy were compared. The DASH score, pain, wrist motion, grip strength and the Mayo wrist score were used to rate the outcome. RESULTS: In 6 patients, neuropathy of the median nerve persisted since injury in spite of carpal tunnel release in 5 of them. 3 patients showed secondary, delayed median nerve affection. Patients with median neuropathy had a worse result with regard to pain at rest, grip force, the DASH score, and the Mayo wrist score. The difference was statistically significant for pain with activities. CONCLUSION: Median neuropathy following perilunar dislocation injuries is frequent. It appears rather like a chronic neural lesion than a typical compression syndrome. A primary carpal tunnel release cannot always prevent persistent neural disorders.

[Injuries of the proximal interphalangeal joint]. / Verletzungen der Mittelgelenke.

BACKGROUND: Injuries of the proximal interphalangeal joint (PIP joint) are common. They are frequently underestimated by patients and initial treating physicians, leading to unfavorable outcomes. Basic treatment includes meticulous clinical and radiological diagnosis as well as anatomical and biomechanical knowledge of the PIP joint. TREATMENT: In avulsions of the collateral ligaments and the palmar plate with or without involvement of bone, nonoperative treatment is preferred. Operative stabilization is reserved for large displaced bony fragments or complex instabilities. In central slip avulsion or rupture, osseous refixation, suture, or reconstruction is common and nonoperative treatment is limited to special situations like minimally displaced avulsions. In basal fractures of the middle phalanx, elimination of joint subluxation and restoration of joint stability are priority. If the fragments are too small for fixation with standard implants, therapeutic alternatives include refixation of the palmar plate, dynamic distraction fixation, percutaneous stuffing, or replacement by a hemihamate autograft. Early motion is initiated regardless of the treatment regime. Undertreatment leads to persistent swelling, instability, and limited range of motion, which are difficult to treat. Contributing factors are unnecessary immobilization, immobilization in more than 20° flexion or transfixation by K-wires. For residual limitations, nonoperative treatment with physiotherapists and splinting is first choice. Operative treatment is reserved for persistent flexion/extension contractures persisting for more than 6 months, as well as reconstructions in boutonniere and swan neck deformity and salvage procedures for destroyed joints.

[Malunion of the distal radius - long-term results after extraarticular corrective osteotomy]. / Die fehlverheilte distale Radiusfraktur - Langzeit-ergebnisse nach extraartikulärer Korrekturosteotomie.

BACKGROUND AND PURPOSE: Numerous reports on short- and mid-term results demonstrate the value of corrective osteotomies for malunion of the distal radius. However, only long-term results can show whether a procedure has stood the test of time. Therefore the main questions to be answered in this article are: (i) are clinical and radiological improvements, recorded at short- and mid-term follow-up, long lasting? (ii) are consecutive procedures required, especially salvage procedures?; and (iii) what about the development of post-traumatic osteoarthritis? PATIENTS AND METHODS: The study is based on the prospective data of 17 patients who underwent an extraarticular corrective osteotomy of the distal radius for symptomatic malunion (13 dorsal and 4 palmar malunions) between August 1992 and August 2003. The corrective osteotomy was performed as an opening wedge osteotomy filling the gap with an iliac crest bone graft and stabilisation of the radius with a plate. In 16 patients the radius was approached from palmar, in one patient the approach was dorsal. Preoperative, at short-term and at long-term postoperative follow-up clinical and radiological examinations were performed. In dorsal malunion the mean short-term follow-up was 17±10 (range: 7-44) months, and the mean long-term follow-up was 157±51 (120-254) months. In palmar malunion, the short-term follow-up averaged 13±6 (7-20) months, and the long-term follow-up 150±10 (138-166) months. RESULTS: All osteotomies showed bony union. One patient had to be excluded from the long-term evaluation due to wrist fusion and ulnar head hemiresection after 15 years. After dorsal malunion the long-term results showed a lasting improvement for all parameters. A comparison of short-term and long-term results revealed no deterioration of the results but a further statistically significant improvement in grip strength. 7 patients had no osteoarthritis, 3 osteoarthritis 1°, 1 osteoarthritis 2°, and 1 osteoarthritis 3°. After palmar malunion improvements occurred and lasted in the long-term run, but were not statistically significant. In this group no osteoarthritis was present. CONCLUSION: Corrective osteotomy for malunion of the distal radius has stood the test of time even in the long-term course. Even from this point of view, it can be recommended.

[Restoration of thumb flexion at the interphalangeal joint by transposition of the flexor digitorum superficialis tendon from the ring finger]. / Wiederherstellung der Daumenendgelenkbeugung durch Transposition der oberflächlichen Beugesehne des Ringfingers.

OBJECTIVE: Restoration of active thumb flexion at the distal joint. INDICATIONS: Loss of active flexion of the interphalangeal (IP) joint of the thumb if there is a transection of the flexor pollicis longus (FPL) tendon at the tendon channel of the thumb or thenar and direct suture is not possible but the tendon channel is intact, as alternative procedure to a free tendon graft if the transection is proximal to the tendon channel and the muscle of the FPL is contracted/injured or the FPL tendon is unharmed but the FPL muscle is partially or complete paralyzed. CONTRAINDICATIONS: Insufficiency of the FPL tendon channel, impairment of the superficial or deep flexor tendon of the ring finger, limited passive motion of the proximal and distal thumb joints, acute local general infection and non-compliance or incapacity of the patient. SURGICAL TECHNIQUE: The surgical technique depends on the necessity of transosseous refixation of the FDS IV at the base of the distal phalanx of the thumb or the possibility of woven sutures through the FPL proximal to the tendon channel. If the tendon channel is intact the distal part of the FPL tendon is shortened to 1 cm, the FDS IV tendon is cut distal to the chiasma of Camper, pulled through the carpal tunnel and moved into the channel of the FPL tendon and fixed transosseously through the base of the distal phalanx of the thumb. If the transection of the FPL tendon is located proximal to the tendon channel and muscle of the FPL is injured, FDS IV tendon will be woven using the Pulvertaft technique through the FPL tendon at the distal forearm. POSTOPERATIVE MANAGEMENT: Postoperative 6 weeks motion of thumb flexion without resistance in relieved position of the thumb through a thermoplast splint and 6 weeks of functional use of the hand with increasing weight bearing. RESULTS: In this study 10 patients with FDS IV transposition to reconstruct an isolated rupture of the FPL tendon could be followed for an average of 4.1 years postoperatively. The active range of motion of the IP joint of the thumb averaged 65° (10-100°), 8/10 patients achieved an equal active and passive range of motion of the IP joint of the thumb, in 2 patients some flexion insufficiency remained, 9 patients could reach the fingertip of the small finger with the thumb and 1 patient lacked 3 mm. Contracture of the proximal thumb joint developed in two patients. After removal of the FDS IV tendon two patients developed contracture of the PIP joint of the ring finger. The grip force was reduced to 81 %, lateral grip to 83 % and pinch grip to 77 %. The DASH score averaged 18 (0-31) and 8/10 patients would choose to undergo this surgery again.

[Treatment of fingertip defect injuries with a semiocclusive dressing according to Mennen and Wiese]. / Behandlung von Fingerkuppendefektverletzungen mit dem Semiokklusionsverband nach Mennen und Wiese.

OBJECTIVE: The goal of conservative treatment of fingertip defects is to restore a stable and bulky pulp with recovery of sensitivity and a good skin quality. INDICATIONS: Traumatic defects of the fingertip with or without involvement of the fingernail and/or exposed distal phalanx. CONTRAINDICATIONS: Fractures of the distal phalanx with dislocation or joint involvement, necessitating an osteosynthesis. Allergy to any component of the dressing material. DRESSING TECHNIQUE: Application of a semiocclusive film dressing (polyurethane, bacteria- and waterproof, water vapor permeable). If necessary, debridement of necrotic tissue can precede the first film application. Until complete epithelialization of the defect, the dressing needs to be changed not more than once a week. Thereby, the wound itself must be kept untouched. FURTHER MANAGEMENT: Patients must be encouraged to move all finger joints with the applied dressing. After healing, the new skin is initially protected during heavy loading and shear stress, e.g., by a leather finger glove. RESULTS: Based on the method of Mennen and Wiese [3], 200 fingertip injuries (some having involvement of the fingernail or exposed distal phalanx) healed within 20-30 days. The pulp was bulky remodeled with good skin quality including the "fingerprint", as well as nearly normal sensitivity. Using this method, Quell et al. [5] reported on 42 fingertip injuries healed within 2-6 weeks. All fingers could be used without limitation; these were free of pain, with remodeled "fingerprint" and barely visible scars, regular perspiration and restored sensitivity (two-point discrimination 2-8 mm).

[Focal myositis as a side effect of antilipidemics - 2 patients with involvement of the forearm]. / Die fokale Myositis als Nebenwirkung von Lipidsenkern - 2 Patienten mit Befall des Unterarms.

Antilipidemics are widely applied to reduce the risk of cardio- and cerebrovascular events. The purpose of this case report is to illustrate the clinical and radiological findings of focal myositis as a side effect of statins and fibrates in 2 patients with forearm involvement. These 2 cases demonstrate that a targeted medical history taking and use of MRI to support the suspected diagnosis, can efficiently facilitate the route to an appropriate therapy.

[Long-term results following denervation of the wrist]. / Langzeitergebnisse nach Handgelenkdenervation.

BACKGROUND: This retrospective study examines long-term follow-up results after complete denervation of the wrist. PATIENTS AND METHODS: Between 1994 and 2000 a total of 61 complete wrist denervations of 59 patients (median age at operation 46 years) were performed. In 2009 29 patients with 30 complete wrist denervations took part in a follow-up examination after an average of 10 years. The mobility of the wrist and the grip force were examined. Pain and satisfaction with the operation were determined by means of a visual analogue scale (VAS) (0-100). The patients were asked about pain reduction and how long it lasted. Further the DASH and the Mayo Wrist Score were evaluated. Radiographs of the denervated wrist were performed and the degree of the degenerative osteoarthritis was determined according to Knirk and Jupiter. RESULTS: In 7 of the 36 patients examined, a partial or total wrist arthrodesis was performed. These patients were excluded from the study. Pain was improved in 28 of the 30 denervated wrists examined, in 22 the improvement lasted until the follow-up examination, whereas in 6 the pain increased after a median of 90 months. The median pain intensity was 10 at rest and 50 with activity; the satisfaction was 90. The median of the extension/flexion was 81% and the grip force 82% in comparison to the opposite hand. The DASH Score was 25 and the Mayo Wrist Score 73. CONCLUSION: Complete denervation of the wrist according to Wilhelm is a treatment option for the chronically painful wrist and can lead to good grip force, mobility, sufficient pain reduction and satisfaction in the long term.

Traction radiography for the diagnosis of scapholunate ligament tears: an experimental cadaver study.

The aim of this experimental cadaver study was to verify that thumb traction radiography can be used to diagnose scapholunate interosseous ligament (SLIL) injury. Eight cadaver forearms were positioned vertically so that the thumb could be held in a Chinese finger trap and traction force applied using a 5 kg weight. Fluoroscopy was performed with the thumb unloaded and under traction, and then unloaded and under traction after division of the SLIL. The scapholunate joint gaps were measured electronically. The difference between the unloaded and loaded wrists with sectioned SLIL was not statistically significant. These results suggest that thumb traction radiography might not reliably detect acute, complete SLIL tears.

[Amputation of the hand as last resort in severe complex regional pain syndrome]. / Amputation der Hand als Ultima ratio bei schwerstem komplexen regionalen Schmerzsyndrom.

In very rare cases, a complex regional pain syndrome type I (CRPS I) of the hand can take a serious, chronic, incurable course. We describe the case of a 36-year-old patient who after reconstruction of a scaphoid fracture developed such a condition. 9 years after the operation an amputation of the hand was performed at the request of the patient after various expert opinions had been obtained and legal action against the insurance provider was successfully concluded. Amputation of the hand can be discussed as a last resort for relief of suffering in cases of severe CRPS I.

[Reconstruction of the distal radioulnar joint using the Herbert ulnar head prosthesis]. / Rekonstruktion des distalen Radioulnargelenks mit der Herbert-Ulnakopfprothese.

OBJECTIVE: To provide painfree forearm rotation in patients with degenerative changes of the distal radioulnar joint (DRUJ). The primary goal is to stabilize the DRUJ in patients with an unstable stump of the distal ulna following resection arthroplasty with the secondary effect of restoring painfree forearm rotation. INDICATIONS: Instability of the distal ulna following various types of resection arthroplasties. Primary or secondary osteoarthritis of the DRUJ. Replacement of an ulnar head destroyed by tumor or trauma. CONTRAINDICATIONS: Longitudinal instability of the forearm (e.g., following an Essex-Lopresti-type of injury, resection of the radial head). Inadequate soft tissue with severe ulnocarpal ligamentous insufficiency. Radial deformity (must be corrected before replacement of the ulnar head). SURGICAL TECHNIQUE: In cases of osteoarthritis of the DRUJ, dorsal exposure of the distal radioulnar joint to the depth of the 5th extensor compartment. Raising of an ulnar-based capsuloretinacular flap by sharp dissection off the ulnar neck proximally and off the dorsal part of the triangular fibrocartilage complex (TFCC) distally. Osteotomy of the distal ulna corresponding to the preoperatively planned size of the prosthesis and removal of the ulnar head, while preserving the attachment of the TFCC within the capsuloretinacular flap. Reaming of the ulnar medullary canal. Insertion of a trial prosthesis. The trial prosthesis has to fit accurately into the shaft with a fluoroscopically documented ulna minus situation of minus 1-2 mm at the wrist joint level. After implanting the definite stem and ulnar head of the Herbert ulnar head prothesis (Martin Medizintechnik®, Tuttlingen, Germany), the capsuloretinacular flap is reattached to the dorsal rim of the sigmoid notch through drilling holes and under advanced tension. In patients with an unstable distal ulnar stump, the operative procedure is technically more demanding as it is more difficult to raise a sufficient capsuloretinacular flap and due to the loss of the ulnar head as an anatomic landmark. POSTOPERATIVE MANAGEMENT: Long arm cast with 70° elbow flexion, 40° forearm supination, and 20° wrist extension for 2 weeks. Subsequently forearm rotation is limited at 40° in a removable ulnar gutter splint. Six weeks postoperatively unlimited active range of motion is allowed and normal activities are gradually commenced. Return to maximum stress 12 weeks postoperatively. RESULTS: Patient satisfaction is high due to an increased forearm rotation, stronger grip force, and remarkable pain relief. In most patients with an unstable distal ulnar stump following resection arthroplasty of the DRUJ, stability can be restored.

[The parallel saw blade]. / Das Parallelsägeblatt.

PROBLEM: For shortening osteotomy, two exactly parallel osteotomies are needed to assure a congruent adaption of the shortened bone after segment resection. This is required for regular bone healing. In addition, it is difficult to shorten a bone to a precise distance using an oblique segment resection. SOLUTION: A mobile spacer between two saw blades keeps the distance of the blades exactly parallel during an osteotomy cut. The parallel saw blades from Synthes® are designed for 2, 2.5, 3, 4, and 5 mm shortening distances. Two types of blades are available (e.g., for transverse or oblique osteotomies) to assure precise shortening. SURGICAL TECHNIQUE: Preoperatively, the desired type of osteotomy (transverse or oblique) and the shortening distance has to be determined. Then, the appropriate parallel saw blade is chosen, which is compatible to Synthes® Colibri with an oscillating saw attachment. During the osteotomy cut, the spacer should be kept as close to the bone as possible. Excessive force that may deform the blades should be avoided. Before manipulating the bone ends, it is important to determine that the bone is completely dissected by both saw blades to prevent fracturing of the corticalis with bony spurs. The shortening osteotomy is mainly fixated by plate osteosynthesis. For compression of the bone ends, the screws should be placed eccentrically in the plate holes. For an oblique osteotomy, an additional lag screw should be used.