Scapholunate ligament reconstruction using a bone-retinaculum-bone autograft: a biomechanic and histologic study

Bone-retinaculum-bone reconstruction of scapholunate ligament injuries

This article describes the indications for the use of a bone-retinaculum-bone autograft in soft tissue reconstruction of the torn scapholunate ligament. Specific surgical technique and postoperative management are highlighted. Initial results of a primary cohort of patients undergoing this technique are described. The technique is mainly indicated for patients with scapholunate ligament tears that are moderately easy to reduce by open methods.

Advances in the in vivo measurement of normal and abnormal carpal kinematics

This article presents the development of an in vivo, three-dimensional methodology using markerless bone registration for examining the normal and abnormal kinematics of the wrist carpal bones. The resulting descriptions of three-dimensional kinematics from healthy patients and patients with documented unilateral scapholunate interosseous ligament injuries are briefly presented.

Osteoligamentoplasty and limited dorsal capsulodesis for chronic scapholunate dissociation

Treatment of chronic scapholunate dissociation remains unsatisfactory. As the dorsal part of scapholunate interosseous ligament (SLIL) seems to be the "critical corner" of the scapholunate stability, its replacement by an analogous structure could restore scapholunate stability. A procedure is described which combines reconstruction of the dorsal region of the SLIL by means of an osteoligamentous autograft, harvested at the carpus (dorsal trapezoidometacarpal II ligament) and limited dorsal capsulodesis. The limited dorsal capsulodesis is performed using the scaphotriquetral head of the dorsal intercarpal ligament left attached to the distal pole of the scaphoid and fixed with a bone anchor on the dorsal aspect of the lunate. The osteoligamentous autograft prevents scapholunate dissociation and dorsal scaphoid subluxation. The dorsal capsulodesis limits scaphoid flexion and allows synergistic scapholunate mobility. This combination should stabilize the scaphoid in the horizontal as well as sagittal planes. The advantages of this technique are: 1) a single incision; 2) replacement of a ligament by an analogous autograft; 3) faster healing by bone-to-bone apposition; 4) more anatomic and physiologic reconstruction. Three patients are presented to illustrate the technique.

What is the Ideal Replacement for the Scapholunate Ligament in a Chronic Dissociation?

An ideal replacement for the scapholunate ligament has not been found. The carpometacarpal bone-ligament-bone complex at the base of the third metacarpal can be used as a replacement for the scapholunate ligament. A cadaveric study of matched scapholunate ligament and third metacarpal-capitate was carried out. Data for stiffness and strength were obtained from fresh frozen specimens tested to failure with a hydraulic distractor. The third metacarpal-scaphoid ligament most closely approximated the stiffness and the strength of the scapholunate ligament. Operative replacement of the scapholunate ligament with the third metacarpal-scaphoid replacement was accomplished. Clinically, the performance of the operation is facile and, in the present study, was not associated with increased morbidity or duration of surgery compared with other options.

This study indicates that the third carpometacarpal ligament approximates the mechanical properties of the scapholunate ligament and is a good alternative for replacement surgery.

Constraint and material properties of the subregions of the scapholunate interosseous ligament

The material and constraint properties of the dorsal, proximal, and palmar regions of the scapholunate ligament were studied using isolated bone-ligament-bone preparations from 24 adult intact cadaver wrists. Determinations of constraint to differential rotation and translation as well as failure strength were made using a servohydraulic testing machine incorporating an additional rotatory actuator. The dorsal region of the scapholunate ligament offered the greatest constraint to differential translation, while both the dorsal and palmar regions demonstrated statistically significant combined constraints to differential rotation between the scaphoid and lunate. The greatest yield strength was found in the dorsal region (260.3 N +/- 118.1 N), followed by the palmar region (117.9 N +/- 21.3 N) and the proximal region (62.7 N +/- 32.2 N).

Autograft replacements for the scapholunate ligament: a biomechanical comparison of hand-based autografts

An ideal replacement for the scapholunate ligament (SLL) has not been found. The carpometacarpal bone-ligament-bone complex at the base of the second and third metacarpal is proposed as a replacement for the SLL in this study. A cadaveric study of matched SLL, second metacarpal-trapezoid ligament, third metacarpal-capitate ligament, and dorsal periosteal retinaculum was performed. Stiffness and strength were obtained from fresh-frozen specimens tested to failure with a hydraulic distractor. The second metacarpal-trapezoid ligament and the third metacarpal-capitate ligament most closely approximated the stiffness and strength of the SLL. The dorsal periosteal retinaculum was significantly less stiff and was significantly weaker than the SLL. This study indicates that the second or third carpometacarpal ligaments are grafts that approximate the mechanical properties of the SLL.

Tarsal autografts for reconstruction of the scapholunate interosseous ligament: a biomechanical study

A biomechanical cadaver study was performed to identify a potential bone-ligament-bone autograft from the foot for reconstruction of the scapholunate interosseous ligament (SLIL). In this study the biomechanical properties of 9 dorsal tarsal ligaments and the anterior tibiofibular ligament were investigated and compared with those of the dorsal part of the SLIL. Fifteen fresh-frozen human cadaver feet and 14 fresh-frozen human cadaver wrists were used. In a Monsanto Tensometer testing apparatus (Monsanto Limited Instruments, Dorean Swindon, England) the complexes were uniaxially elongated at a constant velocity of 6.35 mm/min until rupture occurred. The stiffness and strength values for each tarsal ligament were calculated and compared with those of the dorsal part of the SL ligament. Analysis indicated that the third dorsal tarsometatarsal ligament (143 +/- 42 N) and the dorsal calcaneocuboid ligament (149 +/- 41 N) were comparable to the dorsal part of the SL ligament (141 +/- 20 N) while all other ligaments were stronger. The stiffness values of the third dorsal tarsometatarsal ligament (67 +/- 17 N/mm) and the dorsal calcaneocuboid ligament (55 +/- 14 N/mm) were comparable to the dorsal part of the SL ligament (61 +/- 6 N/mm). All the other ligaments had values that were higher than the dorsal part of the SL ligament. The strongest ligament appeared to be the medial dorsal cuneonavicular ligament (479 +/- 65 N), which had a stiffness value of 127 +/- 19 N/mm. Although the third dorsal tarsometatarsal ligament and the dorsal calcaneocuboid ligament are biomechanically most similar to the dorsal part of the SLIL, at present it is unclear how strength and stiffness values of ligaments are sustained following transplantation. From this selection of tarsal ligaments, the medial dorsal cuneonavicular ligament is the strongest ligament and it is therefore concluded that this ligament is the most suitable ligament to be used as an autograft for reconstruction of the SLIL.

Histology of the extensor retinaculum of the wrist and the ankle

The extensor retinaculum of the wrist has been used for reconstruction of the annular pulleys of the flexor sheath. We examined the histologic structure of the extensor retinaculum and tendon sheath of the wrist and ankle in cadaveric specimens using hematoxylin-eosin and Verhoeff-van Gieson stains to detect elastin and alcian blue to detect hyaluronic acid, comparing the structure with that described previously for the annular pulleys. Three distinct layers are identified in the retinaculums of both the ankle and wrist: the inner gliding layer, with hyaluronic acid-secreting cells, shows isolated chondroid metaplasia; the thick middle layer contains collagen bundles, fibroblasts, and interspersed elastin fibers; and the outer layer consists of loose connective tissue containing vascular channels. This basic 3-layered histologic composition of the extensor retinaculum is carried in anatomic pulleys throughout the body and appears to represent an adaptive mechanism to provide both a smooth gliding surface as well as the mechanical strength to prevent tendon bowstringing. Given the same histologic structure as the annular pulleys, the extensor retinaculum is a reasonable biologic replacement for the reconstruction of deficient annular pulleys. Likewise, the extensor retinaculum of the ankle could be used to reconstruct a deficient retinaculum of the wrist.

Scapholunate ligament reconstruction using a bone-retinaculum-bone autograft

This study was designed to evaluate the use of a locally available bone-retinaculum-bone graft in the reconstruction of the completely torn scapholunate (SL) ligament. Nineteen consecutive patients (14 with dynamic instability and 5 with static instability) underwent SL ligament reconstruction using an autogenous bone-retinaculum-bone graft taken from the third dorsal compartment region. All patients underwent arthroscopy to document a torn SL ligament. The bone plugs on the graft were fitted into the dorsal scaphoid and lunate, respectively, with the retinaculum periosteal soft tissue intervening sleeve arching between these 2 bones. The SL interval was reduced and pinned for 8 weeks with cast immobilization. The follow-up period averaged 3.6 years (minimum, 24 months). Of the 14 patients with dynamic instability, 12 had no pain and 2 had pain with heavy activity of the wrist. Range of motion (ROM) decreased slightly from preoperative values, and grip strength improved 46%. Thirteen patients were completely satisfied and returned to their former work activities, and 1 returned to modified work activities. Of the 5 patients with static instability, 2 had no pain after surgery, 1 had pain with heavy activity, and 2 had constant pain. ROM in this group decreased moderately in extension/flexion from the preoperative values. Grip strength improved 30% from preoperative values. Satisfaction was rated as complete by 1 patient and partial by 2 patients; 2 patients were dissatisfied. Two patients returned to their former jobs, 2 returned to modified duties, and 1 is on disability. Reconstruction of the SL ligament using a bone-retinaculum-bone autograft is predictable in patients with dynamic instability. Use of this technique with static SL instability is questionable; these patients may require a stronger construct to prevent recurrence of the SL gap.