Surgical repair of acute collateral ligament injuries in digits with the mitek bone suture anchor

S U R G I C A L R E P A I R OF A C U T E C O L L A T E R A L L I G A M E N T I N J U R I E S IN D I G I T S W I T H T H E M I T E K B O N E S U T U R E ANCHOR H. KATO, A. MINAMI, M. TAKAHARA, 1. OSHIO, K. HIRACHI and H. KOTAKI

From the Department of Orthopaedic Surgery, HokkaMo University School of Medicine, Sapporo, Japan Eighteen acute grade Ill collateral ligament injuries were treated by using the Mitek bone suture anchor. Seven were thumb metacarpophalangeal joint injuries, and eleven were finger proximal interphalangeal joint injuries. Seventeen patients were followed more than 12 months after surgery. All patients were able to use the digits in daily living activities within 5 weeks after surgery, and return to their original work or sports activities within 12 weeks. Pain was completely relieved in 15 patients. Loss of joint motion averaged 7 ° . In all joints the postoperative lateral stress angle was within 10 ° of that of the contralateral digit.

Journal of Hand Surgery (British and European Volume, 1999)24B: 1." 70 75 finger PIP joints. This report describes our clinical experience and quantitative functional assessment after surgical treatment.

Injuries of the collateral ligament of the metacarpophalangeal ( M C P ) j o i n t of the thumb and the proximal interphalangeal (PIP)joints of the fingers are common in sports or at work. Splinting or immobilization for 3 to 4 weeks is the commonly accepted treatment for grade I and II injuries. However, in grade IlI injuries with complete rupture of the ligament, such conservative treatment often results in pain, instability, and weakness of pinch strength (Louis et al., 1986; Redler and Williams, 1967; Rodriguez, 1973: Wray et al., 1984). Primary repair is usually recommended for grade lII injuries of the collateral ligament of the thumb MCP or finger PIP joints in patients who are manual labourers or involved in sports (Ali, 1984; Bowers, 1986; Derkash et al., 1987; Dray and Eaton, 1993; Heyman et al., 1993; Isani, 1986; Kahler and McCue, 1992). The usual method of repair has been the pull-out wire technique to approximate the avulsed ligament into bone, tying the wire to a button on the skin (Bowers, 1986; Derkash et al., 1987; Downey et al., 1995; Dray and Eaton, 1993; Jackson and McQueen, 1994; McCue et al., 1970). However, the pull-out wire technique has several disadvantages. A pressure sore or sensory neuroma under the button, wound infection around the pull-out wire, or joint contracture due to prolonged immobilization may complicate surgery. The patient must visit the hospital periodically for wound care and cannot use the digit for several weeks until the wire is removed. The initial tension of the repaired ligament may decrease after the subsidence of swelling, resulting in residual joint instability. The Mitek bone suture anchor (Mitek Surgical Products, Norwood, MA, USA) is a nickel-titanium alloy anchor system developed specifically to fix soft tissue firmly to bone (Fig 1) (Goble et al., 1994). It has been mainly used in the field of foot, ankle, and shoulder surgery. Recently a few reports have described its use in fixing soft tissue to bone in the hand (Kozin, 1995; Rehak et al., 1994; Weiland et al., 1997). We have used the Mitek bone suture anchor for primary repair of acute collateral ligament injuries of the thumb MCP and

PATIENTS AND M E T H O D S Eighteen collateral ligaments in digits in 18 patients were repaired using a Mitek bone suture anchor. There were ten men and eight women with an average age of 29 years (range, 13-56). Ten patients were manual labourers, and eight patients were students or white-collar workers involved in sports. Seven patients had collateral ligament injuries of the thumb MCP joint, and 11 had collateral ligament injuries of the PIP joint of a finger. The cause

iii!iii!i Fig 1 Mitek G2 anchor with two strands of 0 Ticron (below) and Mitek mini-anchorwith two strands of 2/0 Ticron (above).The Mitek anchors consist of a titanium body and two arcs with 'memory' that allows the anchor to be fixed securely in the subcortical bone. The diameterof the G2 anchor is 2.4 mm and that of the mini-anchoris 1.8 mm. 70

71

ACUTE C O L L A T E R A L L I G A M E N T INJURIES

of injury was a fall from a height in ten patients, sports in four, a motor vehicle accident in two, and other causes in two. All were acute or subacute injuries and the average interval since injury to surgery was 13 days (range, 2 4 5 days). In three cases the thumb MCP joint showed marked instability without a solid end point when the lateral stress test was performed by manually deviating the injured joint. In four cases there were lateral dislocations at the PIP joint and they were reduced manually. In the remaining 11 cases a contrast medium mixed with lignocaine was injected into the injured joint and the lateral instability was confirmed by stress X-ray films. In all seven thumb MCP joint injuries, the ulnar collateral ligament (UCL) had ruptured at its distal bony attachment. A Stener lesion (Stener, 1962) was observed in five of seven cases. Among PIP joint injuries, the UCL was ruptured in two cases and the radial collateral ligament (RCL) in nine. In all PIP joint injuries, the collateral ligament was ruptured at its proximal bony attachment. At follow-up, patients were questioned about joint pain, the period from surgery to resumption of normal domestic activities, and the period from surgery to resumption of work or sports. In each patient, both the operated and contralateral digits were assessed objectively for range of joint motion, pinch strength, and lateral stress X-ray films were done. The follow-up period averaged 19 months (range, 12-24 months).

OperativeTechnique The operation was performed under axillary block anaesthesia. For UCL injuries of the thumb MCP joint, a curved incision was made 1 cm ulnar to the extensor pollicis longus tendon. The ulnar sensory branch of the superficial radial nerve to the thumb was identified and protected. The adductor aponeurosis was severed and the UCL was exposed. For collateral ligament injuries of the finger PIP joint, a midlateral incision was made, the transverse retinacular ligament was severed and the lateral band was reflected dorsally. The site of the collateral ligament avulsion was then confirmed. A hole was drilled starting exactly at the original attachment site of the collateral ligament. Therefore, for UCL injuries of the thumb MCP joint, the hole was drilled in the palmar and ulnar area of the base of the proximal phalanx, and at the 4 or 8 o'clock positions. The hole was drilled in an oblique direction to the joint surface and in a distal and radial direction. For collateral ligament injuries of the finger PIP joint, the drill hole was started at the lateral aspect of the condyle of the proximal phalanx, at the 3 or 9 o'clock positions and pointed in a proximal direction. The drilling procedure was monitored carefully under an image intensifier. After drilling, the opening of the hole was widened with a surgical burr or a file so that the ruptured ligament could be pulled easily into cancellous bone. Different sizes of bone anchor and suture material were used for the thumb MCP and finger PIP joints. For

the thumb MCP joint, the Mitek G2 anchor, with two threaded strands of size 0 Ticron (Johnson and Johnson Medical, Somerville, N J, USA) was inserted into the phalanx. For the finger PIP joint, the Mitek mini-anchor with two threaded strands of size 2/0 Ticron was placed into the phalanx. The Mitek bone anchor was deeply placed such that the ruptured ligament was buried into the cancellous bone of the phalanx. The position of the anchor was confirmed under an image intensifier control. The stability of the anchor was checked by pulling the thread. The cord-like portion of the avulsed end of the collateral ligament was sutured using two horizontal mattress sutures and two strands of Ticron, and then fixed to the anchor. The sutures were knotted on the surface of the ligament to ensure that the end of the ruptured proper portion of the collateral ligament was embedded in cancellous bone (Fig 2). In addition, the accessory collateral ligament was sutured to the remnant of the ligament with 4/0 nylon sutures. Lateral stress was applied to the joint to confirm the strength of the repaired ligament. After surgery, the thumb was immobilized with a short arm thumb spica splint, and the finger was immobilized with a palmar splint. No percutaneous K-wire fixation was used across the joint. The joint was immobilized in a neutral position. The patients were reviewed 1, 2, 3, 4, and 6 weeks after surgery. Two weeks after surgery, patients were instructed to remove the splint several times a day and to flex and extend the digit gently. Three weeks after surgery, the static splint was removed during the day, and the use of the digit in daily activities was permitted. For a PIP joint, a buddy splint was used on the digit to avoid lateral stress. Six weeks after surgery, the patients started to use the digits gently in manual work or sports activities. RESULTS There was one intraoperative complication. In one case with a little finger PIP joint injury, the Mitek mini anchor penetrated the palmar cortex of the head of the proximal phalanx while it was being inserted. The anchor was removed through the palmar cortex and the ligament was repaired by pull-out wire technique. In the remaining 17 patients the ligament was repaired with the Mitek anchor without any complication, and no anchor was damaged, dislodged or loose at follow-up. No patients complained of sensory disturbance around the wound and there were no instances of reflex sympathetic dystrophy. The overall results for each category in all patients are shown in Tables 1 and 2. Pain was absent in all 17 patients although mild pain after sports activity or heavy manual work was noted in two. All 17 patients could use the digit for daily living activities or office work within 5 weeks of surgery. Manual labourers could perform their original work within 8 weeks of surgery. All patients returned to their original sports such as volleyball, soccer, and basketball within 12 weeks of the

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Fig 2

THE JOURNAL OF HAND SURGERY VOL. 24B No. 1 FEBRUARY 1999

Case 14. A 13-year-old female with an acute radial collateral ligament rupture of the ring finger PIP joint. (a) The radial collateral ligament is torn at its proximal origin (arrow). (b) Two strands of 210 Ticron have been passed through the anchor to fix the torn end of the ligament to the proximal phalanx.

operation, and no patient had a lower performance level than before injury. Loss of joint motion compared with the contralateral joint averaged 7 ° (range, 0-20°). In patients with injuries of the MCP joint of the thumb, the pinch strength between the thumb and index finger was measured. In those with finger PIP joint injuries, the pinch strength between the thumb and the finger was measured. The pinch strength of the injured digit compared with that of

the contralateral hand averaged 98% (range, 88-117%). No patients complained of joint instability. The lateral stress angle of the repaired thumb MCP joint averaged 11° (range, 4-18 °) and that of the unaffected side averaged 11° (range, 6-18 °) (Fig 3). The lateral stress angle of the repaired finger PIP joint averaged 7 ° (range, 3-10°), and that of the unaffected side averaged 6 ° (range, 6-11 °) (Fig 4). In all joints the lateral stress angle was within 10° of that of the contralateral digit.

Table 1--Results after ulnar collateral ligament repair of the metacarpophalangeal joint (MCPJ) of the thumb

Patient

Age Sex

Range of motion of MCPJ Ext.lFle~. (degrees)

Pinch strength compared with unaffeetedside (%)

Lateral stress angle of affected (unaffected) side (degrees)

I

44lM

0/50

92

2

29/M

0/55

94

18 (18)

3

42/F

0/45

93

14 (6)

4

20/M

0/50

102

13 (12)

5

13/M

0/55

90

14 (12)

6

15/M

0/45

88

8 (10)

7

30/M

0/50

110

4 ( 1I)

5 ( I 0)

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ACUTE COLLATERAL LIGAMENT INJURIES

Table 2--Results after collateral ligament repair of the proximal interphalangeal joint (PIP J) of the finger Age Sex

Range of motion of PIPJ Ext./Flex. (degrees)

Pinch strength compared with unaffectedside (%)

8

28lM

-5/110

102

9

28/M

0/100

104

5 (4)

l0

46lM

0/110

107

10 (4)

11

38lF

0/110

93

5 (6)

12

41IF

-51100

115

10 (7)

Patient

Lateral stress angle of affected (unaffected) side (degrees) 9 (4)

13

49lF

-5190

117

7 (11)

14

13IF

01105

92

8 (6)

15

17IF

0/110

95

8 (5)

16

15/M

17

56lM

Fig 3

5ll00 0185

92

3 (4)

98

6 (6)

Case 2. X-ray films of thumb MCP joint before and after surgery. (a) Preoperative lateral stress angle of the thumb MCP joint was 45 °. (b) The collateral ligament has been repaired using a Mitek G2 anchor inserted into the proximal phalanx. Postoperative lateral stress angle was 5°. (c) Postoperative lateral view.

DISCUSSION The diagnostic criteria for grade III injuries remain debatable (Ali, 1984; Bowers, 1986; Derkash et al., 1987; Dray and Eaton, 1993; Frank and Dobyns, 1972; Heyman et al., 1993; Isani, 1986; Kiefhaber et al., 1986; Minamikawa et al., 1993). We considered the absence of an end point when lateral stress was applied to the joint in a slight flexion position to indicate a grade III ligament tear. Lateral stress X-ray combined with an arthrography was useful in diagnosing grade III injuries. When the stress angle obtained with the thumb MCP joint in 30 ° flexion position differed by more than 20 ° from that of the contralateral thumb MCP joint, a grade III thumb MCP collateral ligament injury was

diagnosed. When the lateral stress X-ray taken with the finger PIP joint in 0 ° of extension differed by more than 15° from that of the normal finger PIP joint, a grade III ligament injury was diagnosed. In this study all cases had at least one of these two criteria, and a complete collateral ligament tear was confirmed at surgery. A Stener lesion was found in five of the seven cases with complete UCL injury of the thumb MCP joint in our series. Rehak et al. (1994) used the single-pronged first generation Mitek anchor and Bovard et al. (1994) used the double-pronged second generation Mitek anchor for the treatment of UCL injuries of the thumb MCP joint. Kozin (1995) and Weiland et al. (1997) reported good surgical results in UCL ruptures of the thumb MCP

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THE JOURNAL OF HAND SURGERY VOL. 24B No. I FEBRUARY 1999

Fig 4

Case 14, Preoperative and postoperative X-ray films. (a) Preoperative lateral stress angle of the affected PIP joint was 34 °. (b) The collateral ligament has been repaired using a Mitek mini-anchor placed into the condyle of the proximal phalanx. Postoperative lateral stress angle was 8°. (c) Postoperative lateral view.

joint treated with the second generation Mitek anchor. We have used the second generation Mitek bone anchor in cases of grade III collateral ligament injuries of the thumb MCP joint, as well as the finger PIP joint. Our objective evaluation of pain, pinch power, range of motion found satisfactory results that were similar or superior to previously reported results for digits treated by the pull-out wire technique (Ali, 1984; Downey et al., 1995; Jackson and McQueen, 1994; McCue et al., 1970; Osterman et al., 1981). In our series there were no skin problems, infections, or sensory nerve problems. Wound care and rehabilitation after using the Mitek anchor method is much easier than after the pull-out wire technique. Biomechanical studies of the Mitek anchor have revealed that it possesses sufficient pullout strength for ligament fixation in the hand and most failures of ligament fixation have been due to suture breakage rather than anchor pullout (Buch et al., 1995; Cawley et al., 1993; Weiland et al., 1997). To prevent suture breakage we sutured the ligament to the anchor with two strands of Ticron. Pierre et al. (1995) reported that the biomechanical properties after tendon-to-bone healing were approximately equal at 6 and 12 weeks. Based on this we permitted the patients to move the digit from 2 weeks after surgery, and to use the digits in their manual work or sports 6 weeks after surgery. During this rehabilitation period, there was no case in which the repaired ligament became loose. Despite the advantages in the Mitek anchor method, there are several technical pitfalls in anchor placement. Once the anchor has been inserted into the bone, replace-

ment of an anchor is extremely difficult. The hole for insertion, which determines the site, angle, and depth of the anchor, should therefore be drilled under image intensifier control. In case of the little finger PIP joint, the anchor should be placed carefully to prevent the tip of the anchor penetrating the palmar cortex of the proximal phalanx. After placing the anchor at the proper position, the entrance to the bone hole is enlarged to ensure that the end of the ligament is closely coapted to the cancellous bone. After these procedures the ruptured end of the ligament is fixed to the anchor by suture. If the suture breaks while it is being tied, it is impossible to pass another suture through the hole of the anchor. We threaded the anchor with two Ticron sutures before anchor placement so that even if one suture broke the other could be used. When the ligament is sutured to the anchor, it is important to suture the proper cord-like portion of the collateral ligament to the anchor using a horizontal mattress suture. When the sutures are tied, the knots should be placed on the outer surface of the ligament, so that the ligament is in direct contact with the bone. After the sutures are tied, the strength of the repaired ligament should be tested by applying lateral stress to the joint. References Ali MS (1984). Complete disruplion of collateral mechanism of proximal interphalangealjoint of fingers. Journal of Hand Surgery, 9B: 191 193. Bovard RS, Derkash RS, Freeman JR (1994). Grade Ill avulsion fracture repair on the UCL of the proximal joint of the thumb. Orthopaedic Review, 23: 167 169. Bowers WH (1986). Sprains and joint injuries in the hand. Hand Clinics, 2: 93 98.

ACUTE COLLATERAL LIGAMENT INJURIES Buch BD, Innis E 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. Cawley E Howard M, Lane J, Robertson D, Zaretsky S. Comparative evaluation o f bone suture anchor systems in human cadaverie shoulders: a biomeehanical investigation. San Diego: Don Joy Biomechanics Research Laboratory, 1993. Derkash RS, Matayas JR, Weaver JK et al. (1987). Acute surgical repair of the skier's thumb. Clinical Orthopaedics and Related Research, 216: 2%33. Downey DJ, Moneim MS, Omer GE (1995). Acute gamekeeper's thumb. American Journal of Sports Medicine, 23: 22~226. Dray JG, Eaton RG. Dislocations and ligament injuries in the digits. In: Green DP (Ed.) Operative hand surgery, 3rd edn. New York, Churchill Livingstone, 1993:782 784. Frank WE, Dobyns JS (1972). Surgical pathology of collateral ligamentous injuries of the thumb. Clinical Orthopaedics and Related Research, 83: 102-114. Goble EM, Somers WK, Clark R, Olsen RE (1994). The development of suture anchors for use in soft tissue fixation to bone. American Journal of Sports Medicine, 22: 236-239. Heyman P, Gelberman RH, Duncan K, Hipp JA (1993). Injuries of the ulnar collateral ligament of the thumb metacarpophalangeal joint. Clinical Orthopaedics and Related Research, 292: 165-171. lsani A (1986). Small joint injuries requiring surgical treatment. Orthopedic Clinics of North America, 17:407~119. Jackson M, McQueen MM (1994). Gamekeeper's thumb: a quantitative evaluation of acute surgical repair. Injury, 25:21 23. Kahler DM, McCue FC (1992). Metacarpophalangeal and proximal interphalangeal joint injuries of the hand, including the thumb. Clinics in Sports Medicine, 11:57 76. Kiefhaber TR, Stern PJ, Grood ES (1986). Lateral stability of the proximal interphalangeal joint. Journal of Hand Surgery, 11A: 661 669. Kozin SH (1995). Treatment of thumb ulnar collateral ligament ruptures with the Mitek bone anchor. Annals of Plastic Surgery, 35: 1-5. Louis DS, Huebner J J, Hankin FM (1986). Rupture and displacement of the ulnar collateral ligament of the metacarpophalangeal joint of the thumb. Journal of Bone and Joint Surgery, 68A: 1320-1326.

75 McCue FC, Honner R, Johnson MC, Gieck JH (1970). Athletic injuries of the proximal interphalangeal joint requiring surgical treatment. Journal of Bone and Joint Surgery, 52A: 937-956. Minamikawa Y, Horii E, Amadio PC, Cooney WE Linscheid RL, An KN (1993). Stability and constraint of the proximal interphalangeal joint. Journal of Hand Surgery, 18A: 157 158. Osterman AL, Hayken GD, Bora FWM (1981). A quantitative evaluation of thumb function after ulnar collateral repair and reconstruction. Journal of Trauma, 21: 854-861. Pierre PS, Olson EJ, Elliott JJ, O'Hair KC, McKinney LA, Ryan J (1995). Tendon-healing to cortical bone compared with healing to a cancellous trough. Journal of Bone and Joint Surgery, 77A: 1858 1866. Redler I, Williams JT (1967). Rupture of a collateral ligament of the proximal interphalangeal joint of the fingers. Journal of Bone and Joint Surgery, 49A: 322-326. Rehak DC, Sotereanos DG, Bowman MW, Herndon JH (1994). The Mitek bone anchor: Application to the hand, wrist, and elbow. Journal of Hand Surgery, 19A: 853 860. Rodriguez AL (1973). Injuries to the collateral ligaments of the proximal interphalangeal joints. The Hand, 5:55 57. Stener B (1962). Displacement of the ruptured ulnar collateral ligament of the metacarpo-phalangeal joint of the thumb. Journal of Bone and Joint Surgery, 44B: 869-879. Weiland At, Berner HB, Hotchkiss RN, McCormack RR, Gerwin M (1997). Repair of acute collateral ligament injuris of the thumb metacarpophalangeal joint with an intraosseous suture anchor. Journal of Hand Surgery, 22A: 585-591. Wray RC, Young VL, Holtman B (1984). Proximal interphalangeal joint sprains. Plastic and Reconstructive Surgery, 74:101 107. Received: 11 February 1998 Accepted after revision:3August 1998 H. Kato MD, Department of Orthopaedic Surgery,Hokkaido UniversitySchool of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo 060-8638, Japan. E-mail: upperext(~tara.med.hokudai.ac.jp © 1999The British Societyfor Surgeryof the Hand Article no. jhsb. 1998.0030