William H. Seitz

Ulnar nerve decompression with medial epicondylectomy for neuropathy at the elbow.

Ulnar nerve decompression with medial epicondylectomy was performed in 66 elbows between 1966 and 1986 for compressive ulnar neuropathy at the elbow. This study is an updated review that adds 36 cases to a previously published report on 30 cases. These elbows were graded preoperatively and postoperatively using McGowans grading system. Eighty-three percent improved one or two grades, and 11% improved subjectively although they showed no objective improvement, 3% noted no change, and 3% were subjectively worse. One early case sustained damage to the ulnar collateral ligament with resultant instability. No other complications occurred. The best results were seen in the Grade I and II lesions, whereas those with Grade III lesions were the least predictable. The procedure is technically uncomplicated with minimal morbidity and reliable results.

Biomechanical and clinical evaluation of the epitenon-first technique of flexor tendon repair

Thirteen matched pairs of canine flexor tendons were repaired using both the Epitenon-first and the modified Kessler with an epitendinous running suture. These were then tested to failure with a longitudinal force in an Instron test machine. Human cadaver flexor digitorum profundus tendons were used to determine the cross sectional area of the tendon that is displaced by suture material of the Kessler repair and Epitenon-first core suture. Results of biomechanical testing revealed the epitenon-first technique to be 22% stronger than the modified Kessler technique. Comparison of tendon repair cross sectional contact areas by digital scanning of surface photomicrographs demonstrated 20% of the surface area of the repair is occupied by the knot of the modified Kessler technique, while the core suture of the epitenon-first repair consumed only 2.6% of the cross sectional area. These findings correlate with our clinical results of 26 zone II flexor tendon repairs in 18 patients repaired with the epitenon-first technique over a 4-year period. Of these, there has been one rupture and no repeat operations for lysis of adhesions.

Splint immobilization of gamekeeper's thumb

Thirty-nine patients diagnosed with 40 acute complete ruptures of the ulnar collateral ligament of the thumb metacarpophalangeal joint were treated primarily with thumb spica splint immobilization. Duration of splinting ranged from 8 to 12 weeks. Thirty-four of these injuries (85%) followed for 1 to 5 years (average 2.4 years) healed without significant instability, arthrosis, pain, or stiffness (range of motion within 80% of the contralateral hand). Six ruptures (15%) demonstrated persistent instability and pain at 12 weeks and were treated with surgical reconstruction. Currently accepted guidelines for surgical intervention as primary treatment for ligamentous disruption at the thumb metacarpophalangeal joint may need revision. This study suggests that splint immobilization is an effective primary treatment modality. The minority of patients who demonstrate persistent laxity can be successfully treated surgically with excellent results.

Digital lengthening using the callotasis technique.

A series of 14 lengthenings for congenital and posttraumatic digital deficiency has been carried out in a single stage utilizing individual, half-frame design, digital lengthening devices. These devices have afforded individual digital stability without need for additional external support and have provided between 2.0 cm and 3.5 cm lengthening per digit. In only one case was additional bone grafting necessary and in all cases the projected goal of lengthening was achieved. A slow rate of lengthening (0.25 mm in four daily increments) was associated with a minimal amount of pain, patients were able to utilize their hand for function during the lengthening period, and, in cases where physeal plates have remained open, continued growth has been experienced in the follow-up period.

Biomechanical analysis of pin placement and pin size for external fixation of distal radius fractures

A series of biomechanical analyses were performed to explain the recent reduction in treatment-related complications of external fixation of distal radius fractures using a limited open approach for pin placement and larger 4-mm self-tapping half pins. A comparison of pull-out strength, stress concentration effect, and inherent bending strength of 3− and 4-mm half pins was performed. The effect of proximal pin placement in the radius or in the ulna and the effect of distal pin placement in four, six, or eight metacarpal cortices were determined. These analyses demonstrate that the 4-mm self-tapping half pins result in a significantly higher pull-out strength and only a small decrease in torsional load strength of the bone. They also demonstrate that proximal pin fixation in the radius produces the most stable fixation and that distal pin fixation into six metacarpal cortices produces a strong configuration that does not violate the interosseous muscles of the second intrinsic compartment. The rate of treatment-related complications in the external fixation of distal radius fractures (specifically, pin loosening, bending and breakage, fracture through pin sites, collapse at the fracture site, and intrinsic contracture) are addressed in this study. Such complications can be minimized by using 4-mm pins after central predrilling, with proximal placement in the radius and distal placement through six cortices of the bases of the second and third metacarpals.

Long-term results of callus distraction-lengthening in the hand and upper extremity for traumatic and congenital skeletal deficiencies.

Children born with severe congenital upper-extremity limb deficiencies have been treated with many surgical techniques and use of prosthetic limbs. One surgical technique has involved the elongation of skeletal segments and their surrounding soft-tissue envelope through the process of distraction-lengthening. ### Indications for Application of Distraction-Lengthening Technique Indications for the application of distraction-lengthening techniques include traumatic or congenital bone loss of the humerus and congenital deficiencies such as phocomelia1-4 (Fig. 1). Fig. 1 Radiographs showing distraction-lengthening process in a patient with right-sided phocomelia (A). A half-frame lengthening apparatus was applied laterally (B), with three sets of fixation pins in the scapula and humerus, to allow distraction-lengthening. A stable shoulder and a longer, more functional arm unit are now present (C). In the forearm, traumatic amputation or segmental bone loss can be managed by segmental bone transport to fill a defect gap or to lengthen a short below-the-elbow segment after amputation. The technique may be useful in the treatment of a very short forearm, as can occur in patients with radial or ulnar clubhand (Figs. 2, 3, and 4), or in the treatment of major discrepancies of radial or ulnar length, as can occur in patients with multiple hereditary exostoses. Fig. 2 Radiographs showing the upper limb of a young boy with ulnar agenesis and divergent forearm bones with a dislocated radial head (A). Distraction-lengthening was performed to elongate the ulnar remnant and realign the radiocapitellar joint through distraction (B and C). Photograph of the patient after the performance of muscle transfers to provide pincer grasp between the two forearm bones, similar to the result obtained with a Krukenberg procedure (D). (Fig. 2, A through D, reprinted from: Seitz WH Jr. Distraction lengthening in the hand and upper extremity. In: Green DP, Hotchkiss RN, Pederson WC, Wolfe SW, editors. Green’s operative hand surgery. 5th ed. Philadelphia: …

Pressure–morphology relationship of a released carpal tunnel

We investigated morphological changes of a released carpal tunnel in response to variations of carpal tunnel pressure. Pressure within the carpal tunnel is known to be elevated in patients with carpal tunnel syndrome and dependent on wrist posture. Previously, increased carpal tunnel pressure was shown to affect the morphology of the carpal tunnel with an intact transverse carpal ligament (TCL). However, the pressure–morphology relationship of the carpal tunnel after release of the TCL has not been investigated. Carpal tunnel release (CTR) was performed endoscopically on cadaveric hands and the carpal tunnel pressure was dynamically increased from 10 to 120 mmHg. Simultaneously, carpal tunnel cross‐sectional images were captured by an ultrasound system, and pressure measurements were recorded by a pressure transducer. Carpal tunnel pressure significantly affected carpal arch area (p < 0.001), with an increase of >62 mm2 at 120 mmHg. Carpal arch height, length, and width also significantly changed with carpal tunnel pressure (p < 0.05). As carpal tunnel pressure increased, carpal arch height and length increased, but the carpal arch width decreased. Analyses of the pressure–morphology relationship for a released carpal tunnel revealed a nine times greater compliance than that previously reported for a carpal tunnel with an intact TCL. This change of structural properties as a result of transecting the TCL helps explain the reduction of carpal tunnel pressure and relief of symptoms for patients after CTR surgery.

Carpal tunnel syndrome impairs sustained precision pinch performance

OBJECTIVE The purpose of this study was to investigate effects of carpal tunnel syndrome (CTS) on digit force control during a sustained precision pinch. METHODS Eleven CTS individuals and 11 age- and gender-matched healthy volunteers participated in the study. The subjects were instructed to isometrically pinch an instrumented apparatus for 60s with a stable force output. Visual feedback of force output was provided for the first 30s but removed for the remaining 30s. Pinch forces were examined for accuracy, variability, and inter-digit correlation. RESULTS CTS led to a decrease in force accuracy and an increase in amount of force variability, particularly without visual feedback (p<0.001). However, CTS did not affect the structure of force variability or force correlation between digits (p>0.05). The force of the thumb was less accurate and more variable than that of the index finger for both the CTS and healthy groups (p<0.001). CONCLUSIONS Sensorimotor deficits associated with CTS lead to inaccurate and unstable digit forces during sustained precision pinch. SIGNIFICANCE This study shed light on basic and pathophysiological mechanisms of fine motor control and aids in development of new strategies for diagnosis and evaluation of CTS.

Influence of Index Finger Proximal Interphalangeal Joint Arthrodesis on Precision Pinch Kinematics

PURPOSE To evaluate the impact of proximal interphalangeal (PIP) joint arthrodesis on the kinematics of precision pinch. METHODS Eleven healthy subjects performed index finger-thumb pinch motions under 4 conditions: unrestricted thumb and index finger (CONTROL) and fusion of the PIP joint of the index finger in flexion of 30° (PIP30), 40° (PIP40), and 50° (PIP50). Fusion was simulated with metallic splints. Kinematics of the thumb and index finger were recorded with a motion capture system. RESULTS Proximal interphalangeal joint fusion at 30°, 40°, and 50° restricted maximal pinch span between the thumb tip and index finger tip by 6%, 10%, and 14%, respectively. At the time of pulp contact, PIP fusion led to an increase in index metacarpophalangeal joint flexion angle for the PIP30 condition and an increase in variability of thumb tip location for the PIP50 condition. Furthermore, the dynamic coordination between joint angles throughout the movement was affected by PIP fusion. CONCLUSIONS This study reports impairment in the kinematics of precision pinch associated with index finger PIP joint fusion. A PIP joint fusion at 40° to 50° leads to a more natural precision pinch posture, but it restricts the aperture and reduces pinch precision.

Nonvascularized Toe Phalangeal Transfer and Distraction Lengthening for Symbrachydactyly

Symbrachydactyly describes a spectrum of congenital hand differences consisting of digital loss resulting in fused short fingers. As the principles for distraction lengthening have evolved, the technique of nonvascularized toe phalangeal transfer to the hand with shortened digits has provided patients with improved outcomes. Nonvascularized toe phalanx to hand transplant with distraction lengthening restores functional length to a skeletally deficient, poorly functioning hand while maintaining an overlying layer of vascular and sensate tissue. The primary goal is improvement of digital length to enhance mechanical advantage and prehension. We describe the technique of nonvascularized toe phalangeal transfer and distraction lengthening for symbrachydactyly, including the following steps: nonvascularized proximal toe phalanx harvest, toe phalanx transfer to hand, pin placement, osteotomy, and closure.