Atsuhito Seki

Kinematics of partial and total ruptures of the medial collateral ligament of the elbow

In this study the kinematics of partial and total ruptures of the medial collateral ligament of the elbow are investigated. After selective transection of the medial collateral ligament of 8 osteoligamentous intact elbow preparations was performed, 3-dimensional measurements of angular displacement, increase in medial joint opening, and translation of the radial head were examined during application of relevant stress. Increase in joint opening was significant only after complete transection of the anterior part of the medial collateral ligament was performed. The joint opening was detected during valgus and internal rotatory stress only. After partial transection of the anterior bundle of the medial collateral ligament was performed, there was an elbow laxity to valgus and internal rotatory force, which became significant after transection of 100% of the anterior bundle of the medial collateral ligament and was maximum between 70 degrees to 90 degrees of flexion. No radial head movement was seen after partial or total transection of the anterior bundle of the medial collateral ligament was performed. In conclusion, this study indicates that valgus or internal rotatory elbow instability should be evaluated at 70 degrees to 90 degrees of flexion. Detection of partial ruptures in the anterior bundle of the medial collateral ligament based on medial joint opening and increased valgus movement is impossible.

SHOX Haploinsufficiency as a Cause of Syndromic and Nonsyndromic Short Stature

SHOX in the short arm pseudoautosomal region (PAR1) of sex chromosomes is one of the major growth genes in humans. SHOX haploinsufficiency results in idiopathic short stature and Léri-Weill dyschondrosteosis and is associated with the short stature of patients with Turner syndrome. The SHOX protein likely controls chondrocyte apoptosis by regulating multiple target genes including BNP, Fgfr3, Agc1, and Ctgf. SHOX haploinsufficiency frequently results from deletions and duplications in PAR1 involving SHOX exons and/or the cis-acting enhancers, while exonic point mutations account for a small percentage of cases. The clinical severity of SHOX haploinsufficiency reflects hormonal conditions rather than mutation types. Growth hormone treatment seems to be beneficial for cases with SHOX haploinsufficiency, although the long-term outcomes of this therapy require confirmation. Future challenges in SHOX research include elucidating its precise function in the developing limbs, identifying additional cis-acting enhancers, and determining optimal therapeutic strategies for patients.

Skeletal Deformity Associated with SHOX Deficiency

Abstract. SHOX haploinsufficiency due to mutations in the coding exons or microdeletions involving the coding exons and/or the enhancer regions accounts for approximately 80% and 2–16% of genetic causes of Leri-Weill dyschondrosteosis and idiopathic short stature, respectively. The most characteristic feature in patients with SHOX deficiency is Madelung deformity, a cluster of anatomical changes in the wrist that can be attributed to premature epiphyseal fusion of the distal radius. Computed tomography of SHOX-deficient patients revealed a thin bone cortex and an enlarged total bone area at the diaphysis of the radius, while histopathological analyses showed a disrupted columnar arrangement of chondrocytes and an expanded hypertrophic layer of the growth plate. Recent studies have suggested that perturbed programmed cell death of hypertrophic chondrocytes may underlie the skeletal changes related to SHOX deficiency. Furthermore, the formation of an aberrant ligament tethering the lunate and radius has been implicated in the development of Madelung deformity. Blood estrogen levels and mutation types have been proposed as phenotypic determinants of SHOX deficiency, although other unknown factors may also affect clinical severity of this entity.

A Child with Trigger Wrist Caused by Finger Flexion and Extension: A Case Report

A 9 year-old boy presented with a mass in the left wrist and motion-induced discomfort. The patient had a trigger phenomenon on the palmar side of his wrist caused by extension and flexion of the middle finger. The patient had no significant medical history. A 5-cm mass was visualized extending from the palm over the wrist. The patient did not have finger numbness, motor impairment, thenar muscle atrophy, or a Tinel-like sign of the wrist. X-ray imaging showed no abnormalities. A magnetic resonance image (MRI) showed a mass around a single flexor tendon, a lowintensity mass on T1-weighted images (Fig. 1), and a highintensity mass on T2-weighted images (Fig. 2). Accordingly, the mass was expected to be a ganglion or cyst. On sagittal images, the mass surrounded the flexor tendon. Because the symptoms did not improve, the patient underwent surgery 2 months after he noticed the mass. The mass was excised by opening the carpal tunnel. The flexor digitorum superficialis (FDS) of the middle finger adhering to the mass was enlarged (Fig. 3). Histological analysis showed cystic synovial tissue accompanied by thickened wall, papillary proliferation towards the lumen, fibrin deposition, and lymphocyte infiltration. (Fig. 4). Based on the above findings, the patient was diagnosed with a ganglion adhering to the FDS. One year after surgery, the patient had no discomfort, recurrence, or disturbance in daily living.

Elbow and forearm reconstruction in patients with ulnar dimelia can improve activities of daily living

Ulnar dimelia (mirror hand with double ulna) is a rare congenital anomaly in which both forearm bones develop as a normal ulna and polydactyly is present in the hand, the thumb and radius bone being absent. Elbow and forearm problems remain after removal of excess digits and reconstruction of a radial finger to serve as a thumb to allow prehensile movement in all cases reported in the literature. No reports of elbow reconstruction have been identified, although reports of hand and thumb reconstruction have been published. We present our experience of improved activities of daily living (ADLs) after elbow reconstruction for a patient with ulnar dimelia. The elbow reconstruction led to better forearm range of motion but no significant improvement in elbow flexion.

A Radiographic Method for Evaluation of the Index-Hypoplastic Thumb Angle

PURPOSE Thumb metacarpophalangeal joint radial instability occurs during the pinch motion in patients with hypoplastic thumb because of thumb-index web narrowing. We devised a radiographic technique to measure the thumb-index angle, applied while the patient holds a styrene foam cone, to evaluate the relationship between the thumb and the index finger. We used this technique to compare different types of thumb hypoplasia and the groups before and after surgery. METHODS Twenty patients with hypoplastic thumbs held the styrene foam cone. The average age of the patients was 6.5 years (range, 1.6 to 12.0 y). We obtained an overhead radiograph while the patient held the cone and evaluated the apparent thumb-index web angle, the thumb to index finger metacarpal angle (1-2MCA), and the first metacarpophalangeal angle (1MPA). RESULTS In the 9 unilateral cases, no significant difference was detected between the unaffected side and the affected side in terms of thumb-index web angle, but the data showed meaningful differences in terms of 1-2MCA and 1MPA. In addition, the data showed meaningful differences between the groups before surgery and 2 years after surgery in terms of 1-2MCA and 1MPA. CONCLUSIONS Measuring both 1-2MCA and 1MPA enables evaluation of the severity of the deformity, and these parameters allowed for comparative evaluation of the severity of preoperative and postoperative narrowing of thumb-index web space and the radial instability of the thumb metacarpophalangeal joint. By focusing on these characteristics, we devised a novel approach for imaging of the thumb-index web space.

Modified step-cut osteotomy for correction of post-traumatic cubitus varus deformity: a report of 19 cases.

We reviewed the outcomes of post-traumatic varus deformity treated with modified step-cut osteotomy in 19 patients (average age, 7.4 years; range, 4.3–16.8 years at time of surgery). The average follow-up period was 29.6 months. The mean range of motion was 15.0°/124.7° (extension/flexion) before surgery and 6.8°/132.6° at final follow-up. The humerus–elbow–wrist angle was −21.1° before surgery and 4.2° at final follow-up, with a loss of 4.4° from the value of the humerus–elbow–wrist angle after the surgery. Osteotomy was fixed with Kirschner wires, and, in five cases, chips of excised bone could be inserted to avoid elbow extension. However, in eight cases, usually concerning younger patients, the elbow was fixed in hyperextension higher than 5°. No patient developed postoperative infections or later complications. Only one patient had transient nerve palsy. The modified step-cut osteotomy can precisely and stably correct the varus deformity in the coronal plane, especially in patients under 10 years of age. To avoid radial nerve palsy, we recommend that the retractors be removed sometimes during the operation.

A Modified Step-Cut (Reverse V) Osteotomy to Treat Posttraumatic Cubitus Varus Deformity

[Introduction][1] It is sufficient to correct posttraumatic cubitus varus deformity in only the coronal plane in children under the age of ten years to allow more precise and stable correction, and a modified step-cut (reverse V) osteotomy is one of the best methods. ![Figure][2] [Step 1: Expose the Distal Part of the Humerus][3] With the patient in a lateral decubitus position, expose the distal part of the humerus both medially and laterally, using gentle retraction to avoid radial nerve palsy. ![Figure][2] ![Figure][2] [Step 2: Resect Bone][4] Using a triangular template made prior to surgery, perform the osteotomy. ![Figure][2] [Step 3: Reduce Deformity][5] Increase the degree of correction to reduce the deformity. ![Figure][2] ![Figure][2] [Step 4: Fixation and Skin Closure][6] Cross-pin with Kirschner wires, taking care to avoid hyperextension at the osteotomy site. [Step 5: Postoperative Management][7] Immobilize the elbow with a splint, and permit active motion two to three weeks after surgery. ![Figure][2] ![Figure][2] [Results & Preop./Postop. Images][8] Our case series included eight patients (four male and four female). The average age of the patients at the time of the osteotomy was 6.8 years (range, four to fourteen years). [What to Watch For][9] [Indications][10] [Contraindications][11] [Pitfalls & Challenges][12] [Introduction][1] It is sufficient to correct posttraumatic cubitus varus deformity in only the coronal plane in children under the age of ten years to allow more precise and stable correction, and a modified step-cut (reverse V) osteotomy is one of the best methods. ![Figure][2] [Step 1: Expose the Distal Part of the Humerus][3] With the patient in a lateral decubitus position, expose the distal part of the humerus both medially and laterally, using gentle retraction to avoid radial nerve palsy. ![Figure][2] ![Figure][2] [Step 2: Resect Bone][4] Using a triangular template made prior to surgery, perform the osteotomy. ![Figure][2] [Step 3: Reduce Deformity][5] Increase the degree of correction to reduce the deformity. ![Figure][2] ![Figure][2] [Step 4: Fixation and Skin Closure][6] Cross-pin with Kirschner wires, taking care to avoid hyperextension at the osteotomy site. [Step 5: Postoperative Management][7] Immobilize the elbow with a splint, and permit active motion two to three weeks after surgery. ![Figure][2] ![Figure][2] [Results & Preop./Postop. Images][8] Our case series included eight patients (four male and four female). The average age of the patients at the time of the osteotomy was 6.8 years (range, four to fourteen years). [What to Watch For][9] [Indications][10] [Contraindications][11] [Pitfalls & Challenges][12] [1]: #sec-10 [2]: pending:yes [3]: #sec-11 [4]: #sec-12 [5]: #sec-13 [6]: #sec-14 [7]: #sec-15 [8]: #sec-16 [9]: #sec-17 [10]: #sec-18 [11]: #sec-19 [12]: #sec-20

RECONSTRUCTION OF THE FIRST WEB IN CONGENITAL THUMB ANOMALIES

Reconstruction of the first web is an important technique for thumb adduction contracture accompanying congenital anomalies. Our previous cases have been reviewed here to evaluate and compare the indications, results, and problems for these two techniques. The angle formed by the first and second metacarpals (first-second metacarpal angle; 1-2 MCA) on the anterio-posterior (AP) view of the hand, with the thumb in maximum radial abduction, was measured from X-ray. There were 37 patients (43 hands: 27 males, ten females). The average age at the time of surgery was 6.6 years (range, two to 22 years). The five-flap Z-plasty was performed on 20 hands. The spinner flap was performed on 23 hands. The Spinner flap is indicated when contractures are severe or when the preoperative 1-2 MCA is <20°. The five-flap Z-plasty is indicated when contractures are mild or when the preoperative 1-2 MCA is ≥20°.

Current Concepts in Radial Club Hand

Radial club hand is a complex congenital abnormality of the radial or pre-axial border of the upper extremity. It has a wide range of phenotypes from hypoplasia of the thumb to complete absence of the radius and the first ray. Centralization with tendon transfer is a popular method for maintaining the correct position of radial club hand. On the other hand, various corrections were devised, e.g. radialization after distraction to emphasize the fact that the head of the ulna is positioned under the radial carpal bones and is no longer placed in a slot in the center of the carpus, microvascular epiphysis transfer, gradual correction using Ilizarov method, for Bayne Type III or Type IV. We should pay attention to the recurrence of radial deformity or circulatory impairment with the tension. Lunate excision or ulnar shortening can be selected for tension-free correction. Radialization can be indicated for avoiding the recurrence of radial flexion. However, we should pay attention of the radial protrusion of the ulnar head. For avoiding the recurrence of radial deformity or circulatory impairment, gradual correction using Ilizarov external fixation can be indicated, especially in the cases with severe radial deviation or with short forearm. In the mild cases, Bayne Type I or Type II, radius lengthening is accompanied by a soft-tissue distraction or release at the ulnar carpal joint with keeping wrist and forearm motion without producing growth plate damage.