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SCAPHOLUNATE LIGAMENT REPAIR USING THE MITEKTMBONE ANCHOR
SCAPHOLUNATE LIGAMENT REPAIR USING THE MITEKTM BONE ANCHOR Technique and preliminary results B. BICKERT, M. SAUERBIER and G. GERMANN From the Department of Plastic and Hand Surgery/Burn Centre, BG Trauma Centre, Ludwigshafen and the Department of Plastic and Hand Surgery, University of Heidelberg, Heidelberg, Germany
A retrospective study was done to assess the outcome after repair of completely ruptured scapholunate interosseous ligaments using the MitekTM Mini G2 bone anchor. From 1994 to 1996. 12 patients underwent scapholunate ligament repair using the bone anchor. A follow-up assessment was done at a mean of 19 months postoperatively and revealed excellent or good results in eight patients, satisfactory in two, and poor in two patients, one of whom had developed lunate necrosis. One patient with an excellent functional result demonstrated recurrent dissociation of the scapholunate gap radiographically. The technique described proved to be simpler than conventional procedures in our hands, and yields similar functional results. Journal of Hand Surgery (British and European Volume, 2000) 25B: 2: 188±192 clinical signs of carpal instability, wrist arthroscopy revealed or con®rmed a perilunar pattern of ligament ruptures. Twelve patients in this subgroup had an SL ligament stump which appeared suitable for direct ®xation to bone. Only these patients were treated by the technique described below, and were entered in this study. A follow-up assessment was done at an average of 19 months postoperatively (range, 8±27 months). Patients were asked to answer the German translation of the ``Disability of the Arm, Shoulder, and Hand '' (DASH) questionnaire (Hudak et al., 1996) for subjective evaluation disability and impairment in daily living. This DASH questionnaire contains 23 questions about activities of daily living (part A), and seven questions about symptoms related to the upper extremity (part B) which are answered on a ®ve-step scale. The sum of the results is calculated to a range from 0 (no disability) to 100 (maximal disability). Pain was estimated using a visual-analogue scale (VAS) ranging from 0 (no pain) to 100 (unbearable pain). Only data asking for pain under maximal load were taken into account. Grip strength was measured with an electronic Jamar dynamometer and calculated as a percentage of the strength of the uninjured side. Radiographs were taken in standard posterior±anterior (PA) and lateral views and in a PA view with the ulnar border of the hand elevated 208 from the table [scapholunate gap view of Moneim (1981)]. Additionally, video¯uoroscopy was done with PA and lateral views under stress load (i.e. with the patient moving the wrist into ¯exion, extension, radial and ulnar deviation while compressing a Jamar dynamometer to 20±30 kgf). The cumulative data of pain, DASH, and dierence of the grip strength to the uninjured side were averaged to provide a measure of functional impairment, 0%
Complete rupture of the scapholunate (SL) interosseous ligament causes rotational instability of the scaphoid and lunate, the most common pattern of wrist instability. Its characteristics are dissociation of the scaphoid and lunate, ¯exion and pronation of the scaphoid, and extension of the lunate. If not treated, chronic cases inevitably lead to the clinical picture of scapholunate advanced collapse (SLAC wrist) with loss of carpal height, dorsal subluxation of the capitate, ulnar translation of the lunate, and arthrosis of the radioscaphoid and capitolunate joint surfaces (Watson and Ballet, 1984). The rupture of the scapholunate interosseous ligament has been described as being the ®rst in a sequence of perilunar ligament ruptures that are caused by carpal supination, hyperextension, and ulnar deviation, (May®eld, 1980; May®eld et al., 1980). In these perilunar types of carpal dislocations, the reconstruction of rotational stability between the scaphoid and lunate seems to play the key role in restoring normal wrist kinematics (Short et al., 1995). However, often the SL ligament is shredded to pieces and therefore not suitable for repair. Direct repair, such as primary suture or transosseous ligament ®xation, can only be done when the SL ligament is completely avulsed as an anatomical entity (Lavernia et al., 1992). In particular, the repair should stabilize the stout collagenous dorsal part of the SL ligament (Berger, 1996). Since placing transosseous burr holes into the required positions (Lavernia et al., 1992) has been shown to pose considerable technical diculties, we have used a simpler technique using the MitekTM bone anchor. PATIENTS AND METHODS From June 1994 to October 1996, 178 wrist arthroscopies were carried out. In 54 patients presenting with 188
SL LIGAMENT REPAIR
impairment meaning an excellent and 100% a poor result. Impairment of 0 to 10% was rated excellent, 10 to 30% good, and 30 to 50% satisfactory. Impairment greater than 50% was rated a poor functional result. Operative technique A standard dorsal approach to the radiocarpal joint was used. A lazy-S skin incision was made over the extensor pollicis longus tendon and centered over the scapholunate joint. The third extensor compartment was opened, and the extensor pollicis longus tendon retracted radially. The fourth dorsal compartment was re¯ected ulnarly maintaining its integrity above the plane of the dorsal ligaments of the wrist. Care was taken not to violate the tendon sheaths. The posterior interosseous nerve, easily identi®ed on the ¯oor of the fourth extensor compartment, was coagulated and resected. The radiocarpal joint was exposed through a transverse or, later, a V-shaped incision between the dorsal radiotriquetral and dorsal intercarpal ligaments, the resulting capsular ¯ap being re¯ected radially (Berger and Bishop, 1997; personal communication, 1996). Particular care was taken to save the dorsal intercarpal ligament which may be used for a reversed dorsal capsulodesis in late cases. The proximal pole of the scaphoid and the dorsal horn of the lunate were then exposed. Two joystick K-wires (1.2 mm) were inserted into the scaphoid and the lunate, which helped to expose the scapholunate joint and to reduce the SL dissociation. The next step was the assessment of the dorsal and proximal parts of the SL ligament. Most often the ligament was found to be torn o the scaphoid and still attached to the lunate. However, in rare instances, an avulsion from the lunate or an oblique tear was observed. The avulsion site on the corresponding bone, usually the scaphoid, was thoroughly debrided using a ®ne rongeur, to ensure bony contact of the repaired ligament. A suture anchor (MitekTM Mini G2; Ethicon, Norderstedt, Germany) was armed with a 2/0 nonabsorbable suture (polypropylene), and then inserted into the debrided area of the avulsion. The point of insertion is crucial. The anchor was placed in such a position that the suture would come to lie in a slightly oblique direction in order to resist the rotational forces between scaphoid and lunate. The sutured ligament should pull the scaphoid from its ¯exed position and the lunate from its extended position. Therefore, the anchor was placed dorsally and distally into the scaphoid or proximally into the lunate, respectively. A trial pull on the suture resulted in a ®rm ®t of the anchor tines under the bony cortex. The suture was inserted into the dorsal scapholunate ligament stump distally when the ligament remained
189
attached to the scaphoid, or proximally when it was attached to the lunate. The suture was not tied at this stage. The crucial step was to achieve an anatomical reduction of the SL joint, by closing the SL gap and by extending the scaphoid and ¯exing the lunate to a slight overcorrection, which was greatly facilitated by use of the two joystick K-wires. The reduction was secured by trans®xion with a 1.2 mm K-wire and was always checked ¯uoroscopically. An additional 1.2 mm K-wire was inserted to trans®x the scaphoid tubercle to the capitate. At this point the suture was tied to the bone anchor (Fig 1).
Fig 1 (a) The 2/0 polypropylene suture is passed through the ligament remnant attached to the lunate (L). The suture anchor has been inserted into the scaphoid (S). (b) The suture is tied after anatomical reduction and K-wire trans®xion of the scapholunate joint.
190
The joint capsule was closed with 4/0 absorbable mono®lament suture (polydioxanon). The extensor retinaculum was resutured with the extensor pollicis longus (EPL) tendon in its anatomical position (entrapment of the tendon was not found in this series). Postoperative treatment included splint immobilization for 8 weeks, followed by K-wire removal and physiotherapy. RESULTS All 12 patients were men aged between 24 and 55 (mean, 38) years. Ten patients claimed workers compensation. The typical mechanism of injury was a fall within the range of body height. Five patients had suered a fall from a ladder, and three from a truck. The mean interval between accident and operation was 40 days (range, 4±157). Five patients had additional fractures as well as the ligamentous wrist injury. These were a spinal fracture (L1), a humerus fracture, a radial head fracture, a fracture of the distal radius (C3), and a basal fracture of
THE JOURNAL OF HAND SURGERY VOL. 25B No. 2 APRIL 2000
the ulnar styloid process. All upper extremity fractures were ipsilaterae. Four patients had complete perilunar dislocations (May®eld stage IV), four patients had stage III injuries, two patients had stage II injuries, and two patients had isolated SL ligament ruptures (stage I). The scapholunate ligament was avulsed from the scaphoid in seven patients, from the lunate in three patients, and two patients had oblique tears, so a bone anchor was inserted into each bone. In the stage III and stage IV patients no attempt was made to stabilize the lunotriquetral joint in this series. Radiological assessment revealed stable SL ligaments in ten patients. In these patients, the mean scapholunate angle was 558 (SD 88). Standard radiographs demonstrated a mean width of the SL gap of 3.2 mm (SD 0.8 mm). A normal SL distance of less than 3 mm was found in ®ve patients, and an increased scapholunate gap of 3±4 mm in four patients. Video¯uoroscopy demonstrated normal rotational behaviour of the scaphoid and the lunate under load, therefore the SL ligaments were classi®ed ``stable'' (Figs 2±4). In none
Fig 2 Normal scapholunate distance in (a) ulnar and radial (b) deviation of the wrist. Note the bone anchor in the scaphoid.
SL LIGAMENT REPAIR
191
Fig 3 Scapholunate ligament reattachment to the lunate; normal SL distance in (a) ulnar and (b) radial deviation.
Fig 4 Enlarged scapholunate gap after reattachment of the SL ligament to the scaphoid. Further assessment by video¯uoroscopy under load showed no change of the gap and no rotational instability, so that this SL joint was rated as being stable.
of the patients did the scapholunate distance widen when the hand was moved. There was no correlation between the SL distance and the functional outcome. One patient had an SL gap of 5 mm and was classi®ed ``re-dissociated''. In one patient with necrosis of the lunate, the gap was not measured. The functional outcome was rated as excellent in four patients, good in four, satisfactory in two, and poor in two patients. Among the excellent functional results was the above mentioned patient with a scapholunate redissociation. However, one patient with a poor functional result had a perfect radiological result and full range of motion of wrist and ®nger joints. The other patient who was rated poor had developed necrosis of the lunate, and had undergone subsequent scaphocapitate fusion; at surgery the SL ligament was documented as being healed. The mean pain value was 28 (range, 0±100) for the entire group. The mean DASH score was 21 (SD 14) representing low-grade disability. Overall disability index was 20 (SD 16), also representing good overall function. The mean range of wrist motion was 78% and
192
grip strength was 81% in comparison with the uninjured wrist. The subgroup of nine patients with uneventful healing was scored separately. They mean pain score was 21 (SD 13) on the VAS. Mean grip strength was 78 (SD 26) compared with the uninjured side. The mean range of wrist motion was 77 (SD 12)% of the uninjured side. The mean DASH score was 22 (SD 15). Among these nine patients there were three who reported no pain at all even during heavy work. Three other patients had a grip strength of more than 50 kgf but they reported a certain degree of pain under full stress-loading, for example when removing a wheel weighing 150 kg from a truck or when lifting a marble stone weighing 50 kg. DISCUSSION Repair of the scapholunate ligament seems to improve the long-term functional outcome in perilunar carpal dislocations (Minami and Kaneda, 1993). The ultimate goal of the repair is the restoration of normal rotational behaviour of the scaphoid and lunate. We present a mid-term follow-up study of 12 patients in whom a primary or secondary SL ligament repair was possible using the MitekTM bone anchor. The use of bone anchors to restore rotational stability of the SL joint has been described before. Buch et al. (1995) and Cohen and Taleisnik (1998) mention the use of bone anchors in scapholunate repair but did not specify their technical details or present follow-up results. Packer et al. (1994) reported a case of direct scapholunate ligament suture which was augmented by an additional suture between two bone anchors in the scaphoid and lunate, respectively. In our series, 11 out of 12 repaired scapholunate ligaments provided rotational stability to the scaphoid and lunate. A comprehensive functional and radiological assessment revealed good or excellent results in eight patients. Consecutive follow-up data demonstrate an improvement of the grip strength over a period of more than 18 months, and therefore a further improvement in our patients may be expected. The range of motion exceeded the functional range described by Ryu et al. (1991) in 11 patients. The functional limits expressed by the DASH value were in the low impairment range. However, the number of good and excellent functional results (8/12) was lower than the number of radiographically successfully repaired SL ligaments (11/ 12). This discrepancy may be due to the fact that the follow-up evaluation was entirely based on hard reproducible parameters, namely pain under heavy load, grip strength and impairment in activities of daily living. Weaker parameters such as subjective satisfaction or ability to work were not taken into account. Other groups have reported similar functional outcome results after dislocations of the perilunar type
THE JOURNAL OF HAND SURGERY VOL. 25B No. 2 APRIL 2000
treated by dierent methods (Gabl et al., 1996; Herzberg et al., 1993; Minami and Kaneda, 1993; Sotereanos et al., 1997). Therefore, in some patients the restoration of normal biomechanics may be outweighed by other factors such as soft tissue scarring. In conclusion, direct bony ®xation of the ruptured scapholunate ligament using a suture anchor is generally successfull in restoring scapholunate stability and has produced acceptable functional mid-term results for this dicult-to-treat injury. References Berger RA (1996). The gross and histologic anatomy of the scapholunate interosseous ligament. Journal of Hand Surgery, 21A: 170±178. Berger RA, Bishop AT (1997). A ®ber-splitting capsulotomy technique for dorsal exposure of the wrist. Techniques in Hand and Upper Extremity Surgery, 1: 2±10. Buch BD, Innis P, McClinton MA, Kotani Y (1995). The Mitek Mini G2 suture anchor: biomechanical analysis of use in the hand. Journal of Hand Surgery, 20A: 877±881. Cohen MS, Taleisnik J (1998). Direct ligamentous repair of scapholunate dissociation with capsulodesis augmentation. Techniques in Hand and Upper Extremity Surgery, 2: 18±24. Gabl M, Lutz M, Pechlaner S, Fink C (1996). PerilunaÈre Luxationen und Luxationsfrakturen ± Ergebnisse nach operativer Versorgung. [Perilunate dislocations and dislocation fractures ± results of surgical management]. Der Unfallchirurg, 99: 650±655. Herzberg G, Comtet JJ, Linscheid RL, Amadio PC, Cooney WP, Stalder J (1993). Perilunate dislocations and fracture-dislocations: a multicenter study. Journal of Hand Surgery, 18A: 768±779. Hudak PL, Amadio PC, Bombardier C and the Upper Extremity Collaborative Group (UECG) (1996). Development of an upper extremity outcome measure: The DASH (Disabilities of the Arm, Shoulder, and Hand). American Journal of Industrial Medicine, 29: 602±608. Lavernia CJ, Cohen MS, Taleisnik J (1992). Treatment of scapholunate dissociation by ligamentous repair and capsulodesis. Journal of Hand Surgery, 17A: 354±359. May®eld JK (1980). Mechanism of carpal injuries. Clinical Orthopedics and Related Research, 149: 45±54. May®eld JK, Johnson RP, Kilcoyne RK (1980). Carpal dislocations: pathomechanics and progressive perilunar instability. Journal of Hand Surgery, 5: 226±241. Minami A, Kaneda K (1993). Repair and/or reconstruction of scapholunate interosseous ligament in lunate and perilunate dislocations. Journal of Hand Surgery, 18A: 1099±1106. Moneim MS (1981). The tangential posterioanterior radiograph to demonstrate scapholunate dissociation. Journal of Bone and Joint Surgery, 63A: 1324±1326. Packer GJ, Gill PJ, Stirrat AN (1994). Repair of acute scapholunate dissociation facilitated by the ``TAG'' suture anchor. Journal of Hand Surgery, 19B: 563±564. Ryu JY, Cooney WP, Askew LJ, An KN, Chao EY (1991). Functional ranges of motion of the wrist joint. Journal of Hand Surgery, 16A: 409±419. Short WH, Werner FW, Fortino MD, Palmer AK, Mann KA (1995). A dynamic biomechanical study of scapholunate ligament sectioning. Journal of Hand Surgery, 20A: 986±999. Sotereanos DG, Mitsionis GJ, Giannakopoulos PN, Tomaino MM, Herndon JH (1997). Perilunate dislocation and fracture dislocation: a critical analysis of the volar-dorsal approach. Journal of Hand Surgery, 22A: 49±56. Watson HK, Ballet FL (1984). The SLAC wrist: scapholunate advanced collapse pattern of degenerative arthritis. Journal of Hand Surgery, 9A: 358±365. Received: 18 May 1999 Accepted after revision: 11 October 1999 B. Bickert MD, BG-Unfallklinik Ludwigshafen, Ludwig-Guttmann-Strasse. 13, D-67071 Ludwigshafen, Germany. E-mail: [email protected] # 2000 The British Society for Surgery of the Hand DOI: 10.1054/jhsb.1999.0340, available online at http://www.idealibrary.com on
A retrospective study was done to assess the outcome after repair of completely ruptured scapholunate interosseous ligaments using the MitekTM Mini G2 bone anchor. From 1994 to 1996. 12 patients underwent scapholunate ligament repair using the bone anchor. A follow-up assessment was done at a mean of 19 months postoperatively and revealed excellent or good results in eight patients, satisfactory in two, and poor in two patients, one of whom had developed lunate necrosis. One patient with an excellent functional result demonstrated recurrent dissociation of the scapholunate gap radiographically. The technique described proved to be simpler than conventional procedures in our hands, and yields similar functional results. Journal of Hand Surgery (British and European Volume, 2000) 25B: 2: 188±192 clinical signs of carpal instability, wrist arthroscopy revealed or con®rmed a perilunar pattern of ligament ruptures. Twelve patients in this subgroup had an SL ligament stump which appeared suitable for direct ®xation to bone. Only these patients were treated by the technique described below, and were entered in this study. A follow-up assessment was done at an average of 19 months postoperatively (range, 8±27 months). Patients were asked to answer the German translation of the ``Disability of the Arm, Shoulder, and Hand '' (DASH) questionnaire (Hudak et al., 1996) for subjective evaluation disability and impairment in daily living. This DASH questionnaire contains 23 questions about activities of daily living (part A), and seven questions about symptoms related to the upper extremity (part B) which are answered on a ®ve-step scale. The sum of the results is calculated to a range from 0 (no disability) to 100 (maximal disability). Pain was estimated using a visual-analogue scale (VAS) ranging from 0 (no pain) to 100 (unbearable pain). Only data asking for pain under maximal load were taken into account. Grip strength was measured with an electronic Jamar dynamometer and calculated as a percentage of the strength of the uninjured side. Radiographs were taken in standard posterior±anterior (PA) and lateral views and in a PA view with the ulnar border of the hand elevated 208 from the table [scapholunate gap view of Moneim (1981)]. Additionally, video¯uoroscopy was done with PA and lateral views under stress load (i.e. with the patient moving the wrist into ¯exion, extension, radial and ulnar deviation while compressing a Jamar dynamometer to 20±30 kgf). The cumulative data of pain, DASH, and dierence of the grip strength to the uninjured side were averaged to provide a measure of functional impairment, 0%
Complete rupture of the scapholunate (SL) interosseous ligament causes rotational instability of the scaphoid and lunate, the most common pattern of wrist instability. Its characteristics are dissociation of the scaphoid and lunate, ¯exion and pronation of the scaphoid, and extension of the lunate. If not treated, chronic cases inevitably lead to the clinical picture of scapholunate advanced collapse (SLAC wrist) with loss of carpal height, dorsal subluxation of the capitate, ulnar translation of the lunate, and arthrosis of the radioscaphoid and capitolunate joint surfaces (Watson and Ballet, 1984). The rupture of the scapholunate interosseous ligament has been described as being the ®rst in a sequence of perilunar ligament ruptures that are caused by carpal supination, hyperextension, and ulnar deviation, (May®eld, 1980; May®eld et al., 1980). In these perilunar types of carpal dislocations, the reconstruction of rotational stability between the scaphoid and lunate seems to play the key role in restoring normal wrist kinematics (Short et al., 1995). However, often the SL ligament is shredded to pieces and therefore not suitable for repair. Direct repair, such as primary suture or transosseous ligament ®xation, can only be done when the SL ligament is completely avulsed as an anatomical entity (Lavernia et al., 1992). In particular, the repair should stabilize the stout collagenous dorsal part of the SL ligament (Berger, 1996). Since placing transosseous burr holes into the required positions (Lavernia et al., 1992) has been shown to pose considerable technical diculties, we have used a simpler technique using the MitekTM bone anchor. PATIENTS AND METHODS From June 1994 to October 1996, 178 wrist arthroscopies were carried out. In 54 patients presenting with 188
SL LIGAMENT REPAIR
impairment meaning an excellent and 100% a poor result. Impairment of 0 to 10% was rated excellent, 10 to 30% good, and 30 to 50% satisfactory. Impairment greater than 50% was rated a poor functional result. Operative technique A standard dorsal approach to the radiocarpal joint was used. A lazy-S skin incision was made over the extensor pollicis longus tendon and centered over the scapholunate joint. The third extensor compartment was opened, and the extensor pollicis longus tendon retracted radially. The fourth dorsal compartment was re¯ected ulnarly maintaining its integrity above the plane of the dorsal ligaments of the wrist. Care was taken not to violate the tendon sheaths. The posterior interosseous nerve, easily identi®ed on the ¯oor of the fourth extensor compartment, was coagulated and resected. The radiocarpal joint was exposed through a transverse or, later, a V-shaped incision between the dorsal radiotriquetral and dorsal intercarpal ligaments, the resulting capsular ¯ap being re¯ected radially (Berger and Bishop, 1997; personal communication, 1996). Particular care was taken to save the dorsal intercarpal ligament which may be used for a reversed dorsal capsulodesis in late cases. The proximal pole of the scaphoid and the dorsal horn of the lunate were then exposed. Two joystick K-wires (1.2 mm) were inserted into the scaphoid and the lunate, which helped to expose the scapholunate joint and to reduce the SL dissociation. The next step was the assessment of the dorsal and proximal parts of the SL ligament. Most often the ligament was found to be torn o the scaphoid and still attached to the lunate. However, in rare instances, an avulsion from the lunate or an oblique tear was observed. The avulsion site on the corresponding bone, usually the scaphoid, was thoroughly debrided using a ®ne rongeur, to ensure bony contact of the repaired ligament. A suture anchor (MitekTM Mini G2; Ethicon, Norderstedt, Germany) was armed with a 2/0 nonabsorbable suture (polypropylene), and then inserted into the debrided area of the avulsion. The point of insertion is crucial. The anchor was placed in such a position that the suture would come to lie in a slightly oblique direction in order to resist the rotational forces between scaphoid and lunate. The sutured ligament should pull the scaphoid from its ¯exed position and the lunate from its extended position. Therefore, the anchor was placed dorsally and distally into the scaphoid or proximally into the lunate, respectively. A trial pull on the suture resulted in a ®rm ®t of the anchor tines under the bony cortex. The suture was inserted into the dorsal scapholunate ligament stump distally when the ligament remained
189
attached to the scaphoid, or proximally when it was attached to the lunate. The suture was not tied at this stage. The crucial step was to achieve an anatomical reduction of the SL joint, by closing the SL gap and by extending the scaphoid and ¯exing the lunate to a slight overcorrection, which was greatly facilitated by use of the two joystick K-wires. The reduction was secured by trans®xion with a 1.2 mm K-wire and was always checked ¯uoroscopically. An additional 1.2 mm K-wire was inserted to trans®x the scaphoid tubercle to the capitate. At this point the suture was tied to the bone anchor (Fig 1).
Fig 1 (a) The 2/0 polypropylene suture is passed through the ligament remnant attached to the lunate (L). The suture anchor has been inserted into the scaphoid (S). (b) The suture is tied after anatomical reduction and K-wire trans®xion of the scapholunate joint.
190
The joint capsule was closed with 4/0 absorbable mono®lament suture (polydioxanon). The extensor retinaculum was resutured with the extensor pollicis longus (EPL) tendon in its anatomical position (entrapment of the tendon was not found in this series). Postoperative treatment included splint immobilization for 8 weeks, followed by K-wire removal and physiotherapy. RESULTS All 12 patients were men aged between 24 and 55 (mean, 38) years. Ten patients claimed workers compensation. The typical mechanism of injury was a fall within the range of body height. Five patients had suered a fall from a ladder, and three from a truck. The mean interval between accident and operation was 40 days (range, 4±157). Five patients had additional fractures as well as the ligamentous wrist injury. These were a spinal fracture (L1), a humerus fracture, a radial head fracture, a fracture of the distal radius (C3), and a basal fracture of
THE JOURNAL OF HAND SURGERY VOL. 25B No. 2 APRIL 2000
the ulnar styloid process. All upper extremity fractures were ipsilaterae. Four patients had complete perilunar dislocations (May®eld stage IV), four patients had stage III injuries, two patients had stage II injuries, and two patients had isolated SL ligament ruptures (stage I). The scapholunate ligament was avulsed from the scaphoid in seven patients, from the lunate in three patients, and two patients had oblique tears, so a bone anchor was inserted into each bone. In the stage III and stage IV patients no attempt was made to stabilize the lunotriquetral joint in this series. Radiological assessment revealed stable SL ligaments in ten patients. In these patients, the mean scapholunate angle was 558 (SD 88). Standard radiographs demonstrated a mean width of the SL gap of 3.2 mm (SD 0.8 mm). A normal SL distance of less than 3 mm was found in ®ve patients, and an increased scapholunate gap of 3±4 mm in four patients. Video¯uoroscopy demonstrated normal rotational behaviour of the scaphoid and the lunate under load, therefore the SL ligaments were classi®ed ``stable'' (Figs 2±4). In none
Fig 2 Normal scapholunate distance in (a) ulnar and radial (b) deviation of the wrist. Note the bone anchor in the scaphoid.
SL LIGAMENT REPAIR
191
Fig 3 Scapholunate ligament reattachment to the lunate; normal SL distance in (a) ulnar and (b) radial deviation.
Fig 4 Enlarged scapholunate gap after reattachment of the SL ligament to the scaphoid. Further assessment by video¯uoroscopy under load showed no change of the gap and no rotational instability, so that this SL joint was rated as being stable.
of the patients did the scapholunate distance widen when the hand was moved. There was no correlation between the SL distance and the functional outcome. One patient had an SL gap of 5 mm and was classi®ed ``re-dissociated''. In one patient with necrosis of the lunate, the gap was not measured. The functional outcome was rated as excellent in four patients, good in four, satisfactory in two, and poor in two patients. Among the excellent functional results was the above mentioned patient with a scapholunate redissociation. However, one patient with a poor functional result had a perfect radiological result and full range of motion of wrist and ®nger joints. The other patient who was rated poor had developed necrosis of the lunate, and had undergone subsequent scaphocapitate fusion; at surgery the SL ligament was documented as being healed. The mean pain value was 28 (range, 0±100) for the entire group. The mean DASH score was 21 (SD 14) representing low-grade disability. Overall disability index was 20 (SD 16), also representing good overall function. The mean range of wrist motion was 78% and
192
grip strength was 81% in comparison with the uninjured wrist. The subgroup of nine patients with uneventful healing was scored separately. They mean pain score was 21 (SD 13) on the VAS. Mean grip strength was 78 (SD 26) compared with the uninjured side. The mean range of wrist motion was 77 (SD 12)% of the uninjured side. The mean DASH score was 22 (SD 15). Among these nine patients there were three who reported no pain at all even during heavy work. Three other patients had a grip strength of more than 50 kgf but they reported a certain degree of pain under full stress-loading, for example when removing a wheel weighing 150 kg from a truck or when lifting a marble stone weighing 50 kg. DISCUSSION Repair of the scapholunate ligament seems to improve the long-term functional outcome in perilunar carpal dislocations (Minami and Kaneda, 1993). The ultimate goal of the repair is the restoration of normal rotational behaviour of the scaphoid and lunate. We present a mid-term follow-up study of 12 patients in whom a primary or secondary SL ligament repair was possible using the MitekTM bone anchor. The use of bone anchors to restore rotational stability of the SL joint has been described before. Buch et al. (1995) and Cohen and Taleisnik (1998) mention the use of bone anchors in scapholunate repair but did not specify their technical details or present follow-up results. Packer et al. (1994) reported a case of direct scapholunate ligament suture which was augmented by an additional suture between two bone anchors in the scaphoid and lunate, respectively. In our series, 11 out of 12 repaired scapholunate ligaments provided rotational stability to the scaphoid and lunate. A comprehensive functional and radiological assessment revealed good or excellent results in eight patients. Consecutive follow-up data demonstrate an improvement of the grip strength over a period of more than 18 months, and therefore a further improvement in our patients may be expected. The range of motion exceeded the functional range described by Ryu et al. (1991) in 11 patients. The functional limits expressed by the DASH value were in the low impairment range. However, the number of good and excellent functional results (8/12) was lower than the number of radiographically successfully repaired SL ligaments (11/ 12). This discrepancy may be due to the fact that the follow-up evaluation was entirely based on hard reproducible parameters, namely pain under heavy load, grip strength and impairment in activities of daily living. Weaker parameters such as subjective satisfaction or ability to work were not taken into account. Other groups have reported similar functional outcome results after dislocations of the perilunar type
THE JOURNAL OF HAND SURGERY VOL. 25B No. 2 APRIL 2000
treated by dierent methods (Gabl et al., 1996; Herzberg et al., 1993; Minami and Kaneda, 1993; Sotereanos et al., 1997). Therefore, in some patients the restoration of normal biomechanics may be outweighed by other factors such as soft tissue scarring. In conclusion, direct bony ®xation of the ruptured scapholunate ligament using a suture anchor is generally successfull in restoring scapholunate stability and has produced acceptable functional mid-term results for this dicult-to-treat injury. References Berger RA (1996). The gross and histologic anatomy of the scapholunate interosseous ligament. Journal of Hand Surgery, 21A: 170±178. Berger RA, Bishop AT (1997). A ®ber-splitting capsulotomy technique for dorsal exposure of the wrist. Techniques in Hand and Upper Extremity Surgery, 1: 2±10. Buch BD, Innis P, McClinton MA, Kotani Y (1995). The Mitek Mini G2 suture anchor: biomechanical analysis of use in the hand. Journal of Hand Surgery, 20A: 877±881. Cohen MS, Taleisnik J (1998). Direct ligamentous repair of scapholunate dissociation with capsulodesis augmentation. Techniques in Hand and Upper Extremity Surgery, 2: 18±24. Gabl M, Lutz M, Pechlaner S, Fink C (1996). PerilunaÈre Luxationen und Luxationsfrakturen ± Ergebnisse nach operativer Versorgung. [Perilunate dislocations and dislocation fractures ± results of surgical management]. Der Unfallchirurg, 99: 650±655. Herzberg G, Comtet JJ, Linscheid RL, Amadio PC, Cooney WP, Stalder J (1993). Perilunate dislocations and fracture-dislocations: a multicenter study. Journal of Hand Surgery, 18A: 768±779. Hudak PL, Amadio PC, Bombardier C and the Upper Extremity Collaborative Group (UECG) (1996). Development of an upper extremity outcome measure: The DASH (Disabilities of the Arm, Shoulder, and Hand). American Journal of Industrial Medicine, 29: 602±608. Lavernia CJ, Cohen MS, Taleisnik J (1992). Treatment of scapholunate dissociation by ligamentous repair and capsulodesis. Journal of Hand Surgery, 17A: 354±359. May®eld JK (1980). Mechanism of carpal injuries. Clinical Orthopedics and Related Research, 149: 45±54. May®eld JK, Johnson RP, Kilcoyne RK (1980). Carpal dislocations: pathomechanics and progressive perilunar instability. Journal of Hand Surgery, 5: 226±241. Minami A, Kaneda K (1993). Repair and/or reconstruction of scapholunate interosseous ligament in lunate and perilunate dislocations. Journal of Hand Surgery, 18A: 1099±1106. Moneim MS (1981). The tangential posterioanterior radiograph to demonstrate scapholunate dissociation. Journal of Bone and Joint Surgery, 63A: 1324±1326. Packer GJ, Gill PJ, Stirrat AN (1994). Repair of acute scapholunate dissociation facilitated by the ``TAG'' suture anchor. Journal of Hand Surgery, 19B: 563±564. Ryu JY, Cooney WP, Askew LJ, An KN, Chao EY (1991). Functional ranges of motion of the wrist joint. Journal of Hand Surgery, 16A: 409±419. Short WH, Werner FW, Fortino MD, Palmer AK, Mann KA (1995). A dynamic biomechanical study of scapholunate ligament sectioning. Journal of Hand Surgery, 20A: 986±999. Sotereanos DG, Mitsionis GJ, Giannakopoulos PN, Tomaino MM, Herndon JH (1997). Perilunate dislocation and fracture dislocation: a critical analysis of the volar-dorsal approach. Journal of Hand Surgery, 22A: 49±56. Watson HK, Ballet FL (1984). The SLAC wrist: scapholunate advanced collapse pattern of degenerative arthritis. Journal of Hand Surgery, 9A: 358±365. Received: 18 May 1999 Accepted after revision: 11 October 1999 B. Bickert MD, BG-Unfallklinik Ludwigshafen, Ludwig-Guttmann-Strasse. 13, D-67071 Ludwigshafen, Germany. E-mail: [email protected] # 2000 The British Society for Surgery of the Hand DOI: 10.1054/jhsb.1999.0340, available online at http://www.idealibrary.com on