Congenital flexion deformity of the middle finger and sagittal band hypoplasia

PURPOSE: To report a congenital anomaly of the middle finger. METHOD: Nine patients (16 digits) are reported with congenital flexion deformity of the metacarpophalangeal (MCP) joint of the middle finger. Three patients (4 digits) had isolated deformities to the middle finger and in 6 the deformity was part of congenital ulnar drift (CUD) of the hand. Three patients had Freeman-Sheldon syndrome, 2 had nonsyndromic CUD, and 1 had arthrogryposis multiplex congenita. In CUD patients the middle finger had substantially greater flexion deformity of the MCP joint in comparison with other digits. Seven patients were treated surgically and 2 were treated nonsurgically. Five of the surgical patients had bilateral middle finger involvement. RESULTS: During surgery on 12 digits sagittal band hypoplasia of varying degrees was encountered in all patients and in all patients the extensor tendon of the middle finger was underdeveloped and often ulnarly displaced. Longitudinal imbrication of the remnants of the extensor tendon and centralizing the tendon if necessary by radial sagittal band reefing improved MCP joint flexion deformity. CONCLUSIONS: Congenital middle finger-in-palm deformity in our patients was caused by sagittal band and extensor tendon hypoplasia.     

Chronic painful subluxation of the metacarpal phalangeal joint extensor tendons

Chronic subluxation of the extensor tendons of the metacarpal phalangeal joint has been documented in six patients on active duty in the United States Navy. These patients had painful full flexion and gripping in the knuckle, especially when they were performing their jobs. No extension lag was noted. Three patients had a severed junctura tendinum between the long and index fingers, which was believed to be a contributing factor to extensor tendon subluxation. Local anesthesia was administered to these patients, and the lesions were surgically corrected by reefing of the extensor hood and the sagittal band and repair of the junctura tendinum.     

The sagittal band: anatomic and biomechanical study

Forty-eight digits from 12 human adult fresh-frozen and formalin-preserved cadaveric hands were used to study the anatomy and biomechanics of the sagittal band (SB) and to investigate the mechanism of its injury. The SB was observed to be part of a complex retinacular system in proximity to the metacarpophalangeal (MCP) joint collateral ligaments and the palmar plate. Dynamic changes in SB fiber orientation were observed with different positions of the MCP and wrist joints. The fibers were perpendicular (0 degrees ) to the extensor tendon in neutral position, distally angulated 25 degrees at 45 degrees of MCP flexion, and 55 degrees with full flexion. Swan-Ganz catheter measurements were obtained deep to the SB in varying positions of the MCP joint. The average pressure generation was greatest (50 mm Hg) during full MCP joint flexion and least (30 mm Hg) during 45 degrees flexion. When MCP joint radial or ulnar deviation was added the average measurement was greatest (57) in neutral MCP position and least (35 mm Hg) in 45 degrees flexion. Serial sectioning of the ulnar SB produced no extensor tendon instability. Partial proximal but not distal sectioning of the radial SB produced tendon subluxation. Complete sectioning of the radial SB produced tendon dislocation. Wrist flexion increased tendon instability after radial SB sectioning. We conclude that (1) extensor tendon instability following SB disruption is most common in the long finger and least common in the small finger; (2) ulnar instability of the extensor tendon is due to partial or complete radial SB disruption, (3) the degree of extensor tendon instability is determined by the extent of SB disruption, (4) proximal rather than distal SB compromise contributes to extensor tendon instability, (5) great forces are inflicted on the SB while the MCP joint is in full extension or less frequently in full flexion, which may be the mechanism of its injury, and (6) wrist flexion contributes to extensor tendon instability after SB disruption and may exacerbate the severity of its injury.     

Extensor tendon dislocation in cerebral palsy.

An 18-year-old man with cerebral palsy presented with a flexion deformity of the middle finger particularly at the metacarpophalangeal joint and ulnar dislocation of the extensor tendon. Releasing the tight ulnar sagittal band and imbricating the attenuated radial sagittal band allowed centralization of the extensor tendon. For complete correction of other deformities intrinsic release and extrinsic flexor muscle lengthening were done. Extensor tendon instability in this case was due to the combined forces of the extrinsic and intrinsic muscles on the retinacular system of the extensor mechanism.     

指伸肌腱滑脱的原因分析与手术要点

目的　探讨指伸肌腱滑脱的损伤机制、手术方法和术后复发的关系。方法　 1987年至 1999年 ,在 17例指伸肌腱滑脱手术中 ,在修复矢状束、腱帽和关节囊损伤的同时 ,重视了腱间筋膜的修复。通过模拟实验 ,分析腱间筋膜、矢状束和腱帽在指伸肌腱滑脱中的作用。结果　术后随访 3个月～ 10年 ,17例伸指功能均恢复正常 ,未见复发者。实验结果证实 ,切断指伸肌腱桡侧矢状束和腱帽 ,仅引起指伸肌腱的部分滑脱 ,此时切断腱间筋膜则引起其向尺侧的完全滑脱。结论　矢状束和腱帽损伤的同时 ,伴有腱间筋膜损伤是该症关键的病理机制。手术修复腱间筋膜是防止复发的根本     

Problems and solutions in palliative tendon transfer surgery for radial nerve palsy

Palliative tendon transfer procedures for radial nerve palsy are continuing to evolve. The main modifications have concerned the operative techniques and the choice of procedures to adapt surgery to the needs of the patient. A study of all the elements of tendon transfer has been undertaken and has gradually led us to describe two basic methods of transfer either using or not using the flexor carpi ulnaris for transfer. The essential consideration is the avoidance of radial deviation of the wrist by centralizing the insertion of the extensor carpi radialis longus.     

Effect of radial shortening on muscle length and moment arms of the wrist flexors and extensors

The purpose of this study was to determine the effect of distal radial shortening on muscle length and moment arm of the wrist flexors and extensors. In eight cadaveric upper extremities, distal radius fractures were simulated by an ostectomy. The distal radius was progressively shortened by 2.5, 5.0, 7.5, and 10 mm. Changes in the resting length of the flexor carpi radialis and ulnaris, extensor carpi radialis longus and brevis, and extensor carpi ulnaris muscles were measured with rotary potentiometers at neutral position, flexion, extension, and radial and ulnar deviation of the wrists. The wrists were passively moved through flexion-extension and radioulnar deviation, and tendon excursions and wrist joint angulation were recorded simultaneously. Tendon moment arms were derived from tendon excursions and joint motion. The results showed that either muscle, length or moment arm of the principal wrist flexors and extensors was significantly affected by the radial shortening. Muscle length decreased significantly after radial shortening in all the wrist flexors and extensors except for the extensor carpi ulnaris. The moment arm of the extensor carpi ulnaris tendon decreased significantly during either wrist flexion-extension or radioulnar deviation. The extensor carpi radialis brevis and flexor carpi ulnaris tendons also showed a significant decrease in their moment arms during radioulnar deviation of the wrist. Radial shortening of only 2.5 mm caused statistically significant changes in muscle length and moment arm of the wrist flexors and extensors. Increasing the extent of radial shortening exaggerated the biomechanical changes in the wrist motors. These results validate the importance of normal radial length for wrist kinetics and, from a biomechanical perspective, support complete correction of radial shortening after distal radius fractures.     

Extensor mechanism slide for the treatment of proximal interphalangeal joint extension lag: an anatomic study

PURPOSE: We describe a technique for correction of proximal interphalangeal joint (PIP) extensor lag secondary to angulation and/or shortening of proximal phalanx fractures. METHODS: Proximal phalanx fracture malunions with 2.5 mm of shortening, 5.0 mm of shortening, and apex volar angulation of 40 degrees were simulated in 15 cadaver fingers, creating PIP extensor lags. The metacarpophalangeal (MCP) joint was pinned in neutral. Transection of the ulnar and radial sagittal bands, the extensor digitorum communis (EDC) insertion on the MCP joint capsule, and the juncturae tendinae then was performed. The PIP extensor lag before and after each of the earlier-noted releases was recorded. The MCP joint then was freed and MCP hyperextension was recorded. With the MCP joint in neutral position the sagittal bands then were reapproximated with sutures and MCP extension was measured. RESULTS: The 2.5 mm of axial shortening, 5.0 mm of axial shortening, and 40 degrees of apex volar angulation fracture models produced an average extensor lag of 6.2 degrees , 25.8 degrees , and 42.5 degrees , respectively. Maximal correction of PIP extensor lag required transection of both sagittal bands, EDC insertion on the MCP capsule, and the juncturae tendinae with an average residual extensor lag of -0.8 degrees for the 2.5-mm shortening model, 0.7 degrees for the 5.0-mm shortening model, and 3.2 degrees for the 40 degrees -angulation model. The MCP joint hyperextension increased by 20 degrees to 30 degrees after the releases but decreased to only 1.8 degrees if the sagittal bands were reapproximated to the EDC tendon at their new resting position with the MCP joint in neutral position. CONCLUSIONS: In the cadaver model the PIP extensor lag can be improved substantially by transection of the sagittal bands, release of the EDC insertion on the MCP capsule, transection of the juncturae tendinae, and reapproximation of the sagittal bands to the EDC tendon.     

A unified approach to radial tunnel syndrome and lateral tendinosis

Two of the most common diagnoses assigned to patients presenting with lateral elbow and proximal forearm pain are lateral tendinosis and radial tunnel syndrome. Traditionally, these 2 conditions have been treated as distinct and separate entities with most patients being diagnosed with either one or the other, but not both. The extensor carpi radialis brevis (ECRB) and, to a lesser the degree, a portion of the extensor digitorum communis that form the conjoined lateral extensor tendon are thought to be primarily responsible for the excessive traction that induces lateral tendinosis (a degenerative process of microtears in the tendon with impaired healing), but the supinator blends with these same fibers and shares a role in the pathology. The supinator, primarily the arcade of Frohse, has been thought to play the majority role in compressing the posterior interosseous nerve in radial tunnel syndrome, but the undersurface thick tendon of the ECRB may also cause substantial nerve compression. Reduction of the linear tension transmitted by the ECRB is the common element in the various surgical treatments for lateral tendinosis, performed anywhere from directly at the lateral epicondyle to the distal myotendinous junction. Nerve decompression by division of fascial bands is the goal in surgery for radial tunnel syndrome. These 2 surgical approaches need not be mutually exclusive. In fact, this separation of the 2 clinical entities may play a role in the unpredictable results reported in the literature. This article presents a unified approach to treating both pathologies simultaneously including short-term clinical results.     

Anomalous tendon to the middle finger for sagittal band reconstruction: report of 2 cases

Multiple techniques with good outcomes have been described for sagittal band reconstruction. We describe 2 cases of sagittal band reconstruction using an anomalous slip of the extensor tendon to the middle finger. This anomalous slip can be a resource for surgical reconstruction that can add stability to primary sagittal band repair.     

Medial Patellofemoral Reconstruction Techniques for Patellar Instability

The medial patellofemoral complex (MPFC) is the term used to describe the primary soft tissue stabilizer of the patella, which consists of fibers that attach to the patella (medial patellofemoral ligament, or MPFL), and the quadriceps tendon (medial quadriceps tendon femoral ligament, or MQTFL). Despite the variability of its attachment on the extensor mechanism, the midpoint of this complex is consistently at the junction of the medial quadriceps tendon with the articular surface of the patella, indicating that either patellar or quadriceps tendon fixation can be used for anatomic reconstruction. Multiple techniques exist to reconstruct the MPFC, including graft fixation on the patella, quadriceps tendon, or both structures. Various techniques using several graft types and fixation devices have all reported good outcomes. Regardless of the location of fixation on the extensor mechanism, elements critical to the success of the procedure include anatomic femoral tunnel placement, avoiding placing undue tension on the graft, and addressing concurrent morphological risk factors when present. This infographic reviews the anatomy and techniques for the reconstruction of the MPFC, including graft configuration, type, and fixation, while addressing common pearls and pitfalls in the surgical treatment of patellar instability.     

Subluxation of the Extensor Carpi Ulnaris Tendon Associated with the Extensor Digitorum Tendon Subluxation of the Long Finger

A twenty-year-old male visited our clinic with wrist and long finger metacarpophalangeal (MP) joint pain. Dynamic ultrasonography revealed sagittal band (SB) ulnar subluxation and extensor carpi ulnaris (ECU) volar subluxation. Magnetic resonance imaging showed longitudinal splitting and dislocation of the volar half slip of the ECU tendon. The redundant radial SB was augmented and ECU sheath was advanced to the periosteum using suture anchors. He was able to perform his previous activities at the last follow-up. We encountered a case of "simulateous" ECU dislocation with extensor tendon subluxation of the long finger at the MP joint. Therefore, we report this case with a review of the relevant literature.     

Closed treatment of nonrheumatoid extensor tendon dislocations at the metacarpophalangeal joint

PURPOSE: Acute sagittal band injuries at the metacarpophalangeal (MCP) joint resulting in subluxation or dislocation of the extensor tendons may cause pain and swelling at the MCP joint and limit active extension of the MCP joint. These injuries often are treated with surgical repair or reconstruction. This article outlines a nonsurgical treatment protocol that uses a customized splint for acute, nonrheumatoid extensor tendon dislocations caused by injury to the sagittal bands. METHODS: We retrospectively reviewed 10 patients with 11 acute sagittal band injuries who were treated with a splint of thermally molded plastic that differentially holds the injured MCP joint in 25 degrees to 35 degrees of hyperextension relative to the adjacent MCP joints. All the sagittal band ruptures resulted in complete dislocation of the extensor digitorum communis (EDC) tendon-Rayan and Murray type III injuries. Active proximal interphalangeal and distal interphalangeal motion was begun immediately at the time of initial splinting. The average follow-up period was 14 months. RESULTS: At the time of final evaluation all patients had full range of motion in flexion and extension. Eight patients had no pain and 3 had moderate pain. Four patients (5 digits) had no extensor tendon subluxations and 3 had barely discernable subluxations. Three patients had moderate subluxation of the EDC tendon and their treatments were considered failures. One of these patients had subsequent sagittal band reconstruction. CONCLUSIONS: Our results show acute sagittal band injuries in nonrheumatoid patients resulting in dislocation of the EDC tendon can be managed nonsurgically in many patients with a customized splint called the sagittal band bridge. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level IV.     

Partial extensor carpi radialis longus turn-over tendon transfer for reconstruction of the extensor pollicis longus tendon in the rheumatoid hand: case report

Reconstruction of a distally ruptured extensor pollicis longus tendon in the rheumatoid patient generally involves a tendon transfer or intercalary graft. We present an alternative technique using the radial half of the extensor carpi radialis longus as a turn-over graft. Using the turn-over technique with a half-slip of the extensor carpi radialis longus avoids the traditional limitations of the extensor carpi radialis longus tendon in distal extensor pollicis longus tendon repairs and precludes the need for a free tendon graft.     

Closed sagittal band injury due to low energy trauma

Sagittal band injury is a relatively common cause of extensor tendon subluxation caused by inflammatory disease or high-energy trauma. However, there are few reports in the literature describing sagittal band injury due to low energy trauma. In this report, we describe successful nonsurgical management of a closed sagittal band injury and extensor tendon subluxation associated with low-energy trauma. Patients in 2 cases had no rheumatoid arthritis or history of inflammatory diseases. Conservative treatment resulted in relief of symptoms and corrected the instabilities with no complications.     

Biomechanical evaluation of thumb opposition transfer insertion sites

The optimal location for insertion of the transferred tendon in opposition transfer is controversial. The purpose of this study was to examine 4 commonly used insertion sites into the thumb and determine which maximizes thumb opposition. The flexor digitorum superficialis of the ring finger was used as a donor tendon and was attached in random order to the abductor pollicis brevis (APB) tendon, the APB and extensor pollicis longus, the flexor pollicis brevis (FPB) and dorsal radial extensor hood, and the ulnar extensor hood at the base of the proximal phalanx. As normal opposition was simulated, the minimum distance between the thumb and little finger and the pinch force were measured. The FPB and radial dorsal extensor hood site resulted in the statistically highest pinch force. The FPB and radial dorsal extensor hood and the APB sites had statistically smaller minimum distances between the thumb and little finger than the ulnar extensor hood site. A subjective evaluation of the 3-dimensional thumb path of motion revealed that the FPB and radial dorsal extensor hood site and the APB insertion site allowed the closest approximation of normal thumb opposition. This biomechanical study supports the use of the FPB and radial dorsal extensor hood insertion site or APB insertion site for opposition transfers.     

Tendon transfers for radial, median, and ulnar nerve injuries: current surgical techniques

Tendon transfers are performed predominantly to restore hand function or balance due to injuries of the radial, median, and ulnar nerves. Current surgical techniques for the most common tendon transfers for reconstruction of radial, median, and ulnar nerve palsies are demonstrated. These techniques can also be applied to restore flexion and extension of the fingers and thumb after injuries to the extrinsic flexor and extensor muscles and tendons of the forearm or intrinsic muscles of the hand.     

Extensor digiti minimi tendon "rerouting" transfer in permanent abduction of the little finger

Permanent abduction of the little finger is a bothersome deformity which usually occurs in the context of sequelae of ulnar nerve palsy (Wartenberg's sign), but also in rheumatoid arthritis. The authors report an original technique for correction of this deformity. The extensor digiti minimi tendon is sectioned at its distal insertion and transferred in the wrist through the extensor retinaculum. The "rerouted" tendon is finally resutured distally on the radial aspect of the interosseous muscle. Side-to-side suture of the transferred tendon to the extensor digitorum tendon of the little finger further reinforces the solidity of the procedure. The distal insertion of the extensor digiti minimi tendon is consequently radialized. Its new direction eliminates the abduction component, and the tendon then behaves as an active adductor of the little finger. Five cases (2 cases of ulnar nerve palsy, 3 cases of rheumatoid arthritis) are reported with a mean follow-up of 19 months. All patients have complete active adduction of the little finger in extension, with a persistent capacity for abduction. The other correction techniques published in the literature are discussed.     

Arthroscopic release for lateral epicondylitis: a cadaveric model.

At least 10 different surgical approaches to refractory lateral epicondylitis have been described, including an arthroscopic release of the extensor carpi radialis brevis tendon. The advantages of an arthroscopic approach include an opportunity to examine the joint for associated pathology, no disruption of the extensor mechanism, and a rapid return to premorbid activities with possibly fewer complications. A cadaveric study was performed to determine the safety of this procedure. Ten fresh-frozen cadaveric upper extremities underwent arthroscopic visualization of the extensor tendon and release of the extensor carpi radialis brevis tendon. The specimens were randomized with regard to the use of either a 2.7-mm or a 4.0-mm 30 degree arthroscope through modified medial and lateral portals. Following this, the arthroscope remained in the joint, and the portal, cannula track, and surgical release site were dissected to determine the distance between the cannula and the radial, median, ulnar, lateral antebrachial, and posterior antebrachial nerves, and the brachial artery and the ulnar collateral ligament. No direct lacerations of neurovascular structures were identified; however, the varying course of the lateral and posterior antebrachial nerves place these superficial sensory nerves at risk during portal placement. As in previous reports, the radial nerve was consistently in close proximity to the proximal lateral portal (3 to 10 mm: mean, 5.4 mm). The ulnar collateral ligament was not destabilized. Arthroscopic release of the extensor carpi radialis brevis tendon appears to be a safe, reliable, and reproducible procedure for refractory lateral epicondylitis. Cadaveric dissection confirms these findings.     

Extensor digiti minimi tendon transfer to correct abducted small finger in ulnar dysfunction.

A tendon transfer to correct the abducted posture of the small finger in patients with ulnar nerve dysfunction is described. The extensor digiti minimi is transferred deep to the extensor digitorum communis tendon or junctura tendinae to the small finger and inserted into the radial portion of the extensor hood, correcting the muscle imbalance. Successful results in 10 patients are reported.