- Email: [email protected]
CLINICAL RESULTS OF INTRAARTICULAR FRACTURES OF THE BASE OF THE FIFTH METACARPAL TREATED BY CLOSED REDUCTION AND CAST IMMOBILIZATION
CLINICAL RESULTS OF INTRAARTICULAR FRACTURES OF THE BASE OF THE FIFTH METACARPAL TREATED BY CLOSED REDUCTION AND CAST IMMOBILIZATION J. M. LUNDEEN and A. Y. SHIN From the Division of Hand and Microvascular Surgery, Naval Medical Center, San Diego, California, USA
This retrospective study evaluated the results of closed reduction and cast immobilization for isolated intraarticular fractures of the base of the ®fth metacarpal. Twenty-two of 37 such fractures were available for follow-up at an average of 43 months, and these had all healed at an average of 5 weeks without any cast complications. Twenty patients reported excellent or good results, and two reported fair or poor results. At follow-up, 13 had no arthrosis and nine had mild arthrosis of the carpometacarpal joint. However, outcome was not in¯uenced by fracture type, the degree of subluxation or articular step o, or the presence of arthrosis. We conclude that isolated fractures of the base of the ®fth metacarpal can be reliably treated with closed reduction and cast immobilization. Journal of Hand Surgery (British and European Volume, 2000) 25B: 3: 258±261 Intraarticular fractures through the bases of metacarpal bones are relatively common injuries. Those of the ®rst metacarpal base have been well described, and reliable methods of treatment have been established (Salgeback et al., 1971). In contrast, the treatment of isolated intraarticular fractures of the base of the ®fth metacarpal remains controversial. Although many scattered case reports exist, only four studies include more than ten cases and these recommended a variety of treatment options (Bora and Didizian, 1974; Kjaer-Petersen et al., 1992; Niechajev, 1985; Petrie and Lamb, 1974). Internal ®xation to restore articular congruity is recommended by some authors (HagstroÈm, 1975; Kjaer-Petersen et al., 1992; Niechajev, 1985), whereas others advocate cast immobilization (Bora and Didizian, 1974; Hsu and Curtis, 1970; Shephard and Solomon, 1960) or early unrestricted mobilization (Hunter and Cowen, 1970; Petrie and Lamb, 1974). Weakness of grip (Bora and Didizian, 1974), longer periods of disability and poorer outcome (Hunter and Cowen, 1970) in patients with inadequate reduction of intraarticular fractures through the base of the ®fth metacarpal have been noted by proponents of surgical management. Those recommending conservative treatment have demonstrated the contrary. The purpose of this investigation was to analyse a series of isolated intraarticular fractures of the base of the ®fth metacarpal treated by closed reduction and cast immobilization, so as to assess the long-term clinical results with respect to strength, disability and outcome.
Approval from the institutional review board was obtained prior to initiating the study and contacting patients for follow-up examination. All the records were reviewed for age, sex, hand dominance, mechanism of injury, JAMAR grip strength (JAMAR Hand Dynamometer Model 1, Clifton, NJ, USA), time of immobilization, time to clinical healing and return to duty. All patients underwent initial reduction and cast immobilization by a standardised technique. The ring and little ®ngers were placed in ®nger traps with 5 kg of longitudinal traction; the fractures were then reduced by applying pressure to the dorsal proximal portion of the displaced ®fth metacarpal base with one's index and middle ®ngers and extending the metacarpal with one's thumb. A well moulded short arm plaster cast was then applied and the patient's ring and little ®ngers were secured to this, with their metacarpophalangeal joints ¯exed at 708, using foam-coated aluminum outriggers. Radiographs at the time of injury, post-reduction and at follow-up were obtained. These included anteroposterior, lateral, oblique, 608 supinated, and 308 pronated views of the injured hand. These were evaluated for fracture pattern (Fig 1), based on the classi®cation schemes of Niechajev (1985) and Kjaer-Peterson et al. (1992), ulnar and proximal subluxation (Fig 2), intraarticular step o (Fig 3) and arthrosis. The degree of arthrosis in the ®fth carpometacarpal joint was graded from zero (normal) to three (extensive) based on the arthritis grading scale of Knirk and Jupiter (1986) (Table 1). Patients who were available for follow-up underwent a complete examination of their hands, including measurement of grip strength, clinical examination of the ®fth carpometacarpal joint, neurovascular and motor function assessment and radiographs. Grip strength of the injured hand was calculated as a percentage of the contralateral, uninjured hand. Each patient evaluated his injured hand in comparison to his uninjured hand with respect to pain and other symp-
PATIENTS AND METHODS A review of medical records was performed to identify skeletally mature patients with isolated, closed, intraarticular fractures of the base of the ®fth metacarpal treated by closed reduction and cast immobilization. 258
INTRAARTICULAR FRACTURES OF THE FIFTH METACARPAL BASE
259
Fig 1 Classi®cation of fracture pattern based on the schemes of Niechajev (1985) and Kjaer-Peterson (1992).
Fig 3 Intraarticular step o was de®ned as the parallel distance between the fracture fragments.
Table 1ÐPost-traumatic osteoarthritis grading scale (Knirk and Jupiter, 1986)
Fig 2 The degree of ulnar and proximal subluxation is calculated by measuring the width of the hamate-®fth metacarpal base articulation (x) and the overhang of the ®fth metacarpal base (y).
toms, function, strength and disability, and evaluated the overall outcome as excellent, good, fair or poor. Statistical analysis was performed using the paired Student's t-test and a Wilcoxon rank-sum test. RESULTS Between July 1991 and November 1994, 37 patients who ful®lled the inclusion criteria for the study were identi®ed. Of the 37 patients, 22 were available for
Grade
Findings
0 1 2 3
None Slight joint space narrowing Marked joint space narrowing, osteophyte formation Bone on bone, osteophyte formation, cyst formation
follow-up radiographs and examination. The remaining 15 patients were unable to return for evaluation because of military commitments, geographic consideration or disengagement from the military. The average age of the patients was 29 years (range, 20±60 years), 20 were males and 21 were active duty military personnel. The average length of follow-up was 43 months (range, 30±168 months). Twenty of the 22 patients injured their dominant hands. The mechanism of injury was striking a hard object with a closed ®st in 17 patients, and a direct blow to the base of the ®fth metacarpal in ®ve. Initial radiographs identi®ed four Type A fractures, ten Type B fractures, six Type C fractures and two Type D fractures (Fig 1). The initial injury radiographs demonstrated an average of 15% (range, 0±60%) subluxation and an average of 2 mm of articular step o (range, 0±5 mm; Figs 1 and 2).
260
The average time of cast immobilization and clinical healing were both 5 weeks (range, 4±7 weeks). There were no complications of cast immobilization, such as skin breakdown and ®nger joint contractures. The average time to return to full duty (deployable military condition) in the 21 active duty patients was 6 weeks (range, 4±10 weeks). Average grip strength of the injured hand was 98% (range, 73%±119%) of the grip strength of the contralateral hand at follow-up and was not in¯uenced by fracture pattern (P=0.3), intraarticular step-o (P=0.7) or fracture subluxation (P=0.4). Thirteen patients reported an excellent result, seven a good result, one a fair result and one a poor result with respect to pain, function, disability and grip strength. Subjectively, eight of the 22 patients had intermittent pain, and one of these also complained of weakness, while another experienced intermittent tingling and stiness of the little ®nger. No patient was disabled or on disability at the time of follow up. The clinical outcome was not determined by the fracture pattern (P=0.8), intraarticular step-o (P=0.8), or fracture subluxation (P=0.7). Correlation of subjective outcome with grip strength of the injured hand approached statistical signi®cance (P=0.052). There were no nonunions or malunions but nine patients had mild arthrosis (Grade 1). There were no cases of more severe arthrosis and there was no statistical relationship between the presence of degenerative changes and fracture pattern (P=0.5), intraarticular stepo (P=0.7), fracture subluxation (P=0.8), grip strength (P=0.2), or subjective outcome (P=0.8). DISCUSSION Clement (1945) ®rst described an isolated intraarticular fracture of the base of the ®fth metacarpal. Since then multiple case reports and series have been published but the optimal treatment of these fractures remains uncertain (Bora and Didizian, 1974; Hagstrom, 1975; Hus and Curtis, 1970; Hunter and Cowen, 1970; KjaerPetersen et al., 1992; Lilling and Weinberg, 1979; Niechajev, 1985; Petrie and Lamb, 1974; SaÈlgeback et al., 1971). Striking a hard object with a closed ®st was the most frequent single cause of an intraarticular fracture of the base of the ®fth metacarpal in our, and others, series (Lilling and Weinberg, 1979; Niechajev, 1985). In most cases a force acting on the head of the metacarpal causes a subcapital fracture (metacarpal neck), but in some cases fracture at the metacarpal base occurs. Instability of intraarticular fractures of the ®fth metacarpal base is primarily due to the strong, unopposed proximal pull of the extensor carpi ulnaris which causes ulnar and dorsal subluxation of the main fracture fragment. The radial fragment at the base of the ®fth metacarpal is held in place by the sturdy interosseous metacarpal ligament
THE JOURNAL OF HAND SURGERY VOL. 25B No. 3 JUNE 2000
which connects the bases of the fourth and ®fth metacarpals. The ®rst comprehensive study to look exclusively at isolated intraarticular fractures of the base of the ®fth metacarpal was by Petrie and Lamb (1974). In a review of 19 cases treated conservatively with early active mobilization, they found minimal loss of grip strength and an average time o work of 3 weeks. Only one patient had signi®cant pain and they concluded that good results could be expected with early unrestricted mobilization. However, Bora and Didizian (1974) recognised decreased grip strength as the major functional disability after inadequate reduction of these fractures. In a retrospectively review of 25 cases they concluded that minimally displaced fractures are adequately treated with a molded cast, but fractures that are signi®cantly displaced are best treated by either closed reduction and percutaneous pinning or open reduction and internal ®xation. Grip strength was noted to be decreased in those which united with signi®cant displacement. Unfortunately, the authors failed to quantify their grip strength measurements and did not clearly de®ne ``signi®cant'' displacement. Niechajev (1985) performed a retrospective review of 23 fractures, which were either treated by closed reduction and percutaneous pinning or open reduction and internal ®xation. He reported ``good'' results based on the subjective functional recovery, the absence of persistent tenderness and the measurement of grip strength. KjaerPetersen and coworkers (1992) analysed a series of 64 intraarticular fractures of the base of the ®fth metacarpal with special emphasis on the method of treatment and the functional results. Both conservative and operative methods of treatment were used, and they reported that the alignment of 63% of the fractures was improved with open reduction and internal ®xation, compared with only 20% for those treated with closed reduction and casting. However, the quality of the fracture reduction did not in¯uence the outcome: nine of 20 patients treated conservatively had symptoms at follow-up compared to nine of 23 patients treated with pin ®xation. Despite these ®ndings, these authors recommended restoration of articular congruity and internal ®xation for displaced fractures. In contrast the present study has shown that closed reduction and castings is an adequate and reliable treatment method for intraarticular fractures of the base of the ®fth metacarpal. All fractures healed quickly (average, 5 weeks) and all active duty military patients returned to full duty status after an average of 6 weeks. Persistent symptoms at an average follow-up of 43 months were minimal and grip strength was equivalent to that of the uninvolved hand. Severe arthrosis was not observed, although mild arthrosis was noted in nine carpometacarpal joints. The presence or absence of these mild degenerative changes did not in¯uence outcome and all but one patient was satis®ed.
INTRAARTICULAR FRACTURES OF THE FIFTH METACARPAL BASE
We recognize that there are several limitations to this study. Selection bias towards less severe fracture patterns being treated conservatively may have existed, but our review of fracture patterns and fracture displacement suggests otherwise: most of our fractures had a signi®cant amount of intraarticular displacement and eight of the 22 fractures were comminuted. Additional limitations include the retrospective nature of this study and the relatively short follow-up period with respect to the development of osteoarthritis. Despite these limitations, we feel that our study demonstrates that closed treatment of isolated intraarticular fractures of the base of the ®fth metacarpal can be reliably treated with cast immobilization. References Bora FW, Didizian NH (1974). The treatment of injuries to the carpometacarpal joint of the little ®nger. Journal of Bone and Joint Surgery, 56A: 1459±1463. Clement BL (1945). Fracture±dislocation of the base of the ®fth metacarpal. A case report. Journal of Bone and Joint Surgery, 27A: 498±499. HagstroÈm P (1975). Fracture dislocation in the ulnar carpometacarpal joints. Open reduction and pinning ± a case report. Scandinavian Journal of Plastic and Reconstructive Surgery, 9: 249±251.
261 Hsu JD, Curtis RM (1970). Carpometacarpal dislocations on the ulnar side of the hand. Journal of Bone and Joint Surgery, 52A: 927±930. Hunter JM, Cowen NJ (1970). Fifth metacarpal fractures in a compensation clinic population. A report on one hundred and thirty-three cases. Journal of Bone and Joint Surgery, 52A: 1159±1165. Kjaer Petersen K, Jurik AG, Petersen LK (1992). Intra-articular fractures at the base of the ®fth metacarpal. A clinical and radiographical study of 64: cases. Journal of Hand Surgery, 17B: 144±147. Knirk JL, Jupiter JB (1986). Intra-articular fractures of the distal end of the radius in young adults. Journal of Bone and Joint Surgery, 68A: 647±659. Lilling M, Weinberg H (1979). The mechanism of dorsal fracture dislocation of the ®fth carpometacarpal joint. Journal of Hand Surgery, 4A: 340±342. Niechajev I (1985). Dislocated intra-articular fractures of the base of the ®fth metacarpal: a clinical study of 23 patients. Plastics and Reconstructive Surgery, 75: 406±410. Petrie PWR, Lamb DW (1974). Fracture subluxation of the base of the ®fth metacarpal. The Hand, 6: 82±86. SaÈlgeback S, Eiken O, Carstam N, Ohlsson NM (1971). A study of Bennett's fracture. Special reference to ®xation by percutaneous pinning. Scandinavian Journal of Plastic and Reconstructive Surgery, 5: 142±148. Shephard E, Solomon DJ (1960). Carpo-metacarpal dislocation. Report of four cases. Journal of Bone and Joint Surgery, 42B: 772±777.
Received: 23 November 1999 Accepted after revision: 24 March 2000 Alexander Y. Shin MD, Department of Orthopaedic Surgery, Naval Medical Center San Diego, San Diego, CA 92134-500, USA. # 2000 The British Society for Surgery of the Hand DOI: 10.1054/jhsb.2000.0413, available online at http://www.idealibrary.com on
This retrospective study evaluated the results of closed reduction and cast immobilization for isolated intraarticular fractures of the base of the ®fth metacarpal. Twenty-two of 37 such fractures were available for follow-up at an average of 43 months, and these had all healed at an average of 5 weeks without any cast complications. Twenty patients reported excellent or good results, and two reported fair or poor results. At follow-up, 13 had no arthrosis and nine had mild arthrosis of the carpometacarpal joint. However, outcome was not in¯uenced by fracture type, the degree of subluxation or articular step o, or the presence of arthrosis. We conclude that isolated fractures of the base of the ®fth metacarpal can be reliably treated with closed reduction and cast immobilization. Journal of Hand Surgery (British and European Volume, 2000) 25B: 3: 258±261 Intraarticular fractures through the bases of metacarpal bones are relatively common injuries. Those of the ®rst metacarpal base have been well described, and reliable methods of treatment have been established (Salgeback et al., 1971). In contrast, the treatment of isolated intraarticular fractures of the base of the ®fth metacarpal remains controversial. Although many scattered case reports exist, only four studies include more than ten cases and these recommended a variety of treatment options (Bora and Didizian, 1974; Kjaer-Petersen et al., 1992; Niechajev, 1985; Petrie and Lamb, 1974). Internal ®xation to restore articular congruity is recommended by some authors (HagstroÈm, 1975; Kjaer-Petersen et al., 1992; Niechajev, 1985), whereas others advocate cast immobilization (Bora and Didizian, 1974; Hsu and Curtis, 1970; Shephard and Solomon, 1960) or early unrestricted mobilization (Hunter and Cowen, 1970; Petrie and Lamb, 1974). Weakness of grip (Bora and Didizian, 1974), longer periods of disability and poorer outcome (Hunter and Cowen, 1970) in patients with inadequate reduction of intraarticular fractures through the base of the ®fth metacarpal have been noted by proponents of surgical management. Those recommending conservative treatment have demonstrated the contrary. The purpose of this investigation was to analyse a series of isolated intraarticular fractures of the base of the ®fth metacarpal treated by closed reduction and cast immobilization, so as to assess the long-term clinical results with respect to strength, disability and outcome.
Approval from the institutional review board was obtained prior to initiating the study and contacting patients for follow-up examination. All the records were reviewed for age, sex, hand dominance, mechanism of injury, JAMAR grip strength (JAMAR Hand Dynamometer Model 1, Clifton, NJ, USA), time of immobilization, time to clinical healing and return to duty. All patients underwent initial reduction and cast immobilization by a standardised technique. The ring and little ®ngers were placed in ®nger traps with 5 kg of longitudinal traction; the fractures were then reduced by applying pressure to the dorsal proximal portion of the displaced ®fth metacarpal base with one's index and middle ®ngers and extending the metacarpal with one's thumb. A well moulded short arm plaster cast was then applied and the patient's ring and little ®ngers were secured to this, with their metacarpophalangeal joints ¯exed at 708, using foam-coated aluminum outriggers. Radiographs at the time of injury, post-reduction and at follow-up were obtained. These included anteroposterior, lateral, oblique, 608 supinated, and 308 pronated views of the injured hand. These were evaluated for fracture pattern (Fig 1), based on the classi®cation schemes of Niechajev (1985) and Kjaer-Peterson et al. (1992), ulnar and proximal subluxation (Fig 2), intraarticular step o (Fig 3) and arthrosis. The degree of arthrosis in the ®fth carpometacarpal joint was graded from zero (normal) to three (extensive) based on the arthritis grading scale of Knirk and Jupiter (1986) (Table 1). Patients who were available for follow-up underwent a complete examination of their hands, including measurement of grip strength, clinical examination of the ®fth carpometacarpal joint, neurovascular and motor function assessment and radiographs. Grip strength of the injured hand was calculated as a percentage of the contralateral, uninjured hand. Each patient evaluated his injured hand in comparison to his uninjured hand with respect to pain and other symp-
PATIENTS AND METHODS A review of medical records was performed to identify skeletally mature patients with isolated, closed, intraarticular fractures of the base of the ®fth metacarpal treated by closed reduction and cast immobilization. 258
INTRAARTICULAR FRACTURES OF THE FIFTH METACARPAL BASE
259
Fig 1 Classi®cation of fracture pattern based on the schemes of Niechajev (1985) and Kjaer-Peterson (1992).
Fig 3 Intraarticular step o was de®ned as the parallel distance between the fracture fragments.
Table 1ÐPost-traumatic osteoarthritis grading scale (Knirk and Jupiter, 1986)
Fig 2 The degree of ulnar and proximal subluxation is calculated by measuring the width of the hamate-®fth metacarpal base articulation (x) and the overhang of the ®fth metacarpal base (y).
toms, function, strength and disability, and evaluated the overall outcome as excellent, good, fair or poor. Statistical analysis was performed using the paired Student's t-test and a Wilcoxon rank-sum test. RESULTS Between July 1991 and November 1994, 37 patients who ful®lled the inclusion criteria for the study were identi®ed. Of the 37 patients, 22 were available for
Grade
Findings
0 1 2 3
None Slight joint space narrowing Marked joint space narrowing, osteophyte formation Bone on bone, osteophyte formation, cyst formation
follow-up radiographs and examination. The remaining 15 patients were unable to return for evaluation because of military commitments, geographic consideration or disengagement from the military. The average age of the patients was 29 years (range, 20±60 years), 20 were males and 21 were active duty military personnel. The average length of follow-up was 43 months (range, 30±168 months). Twenty of the 22 patients injured their dominant hands. The mechanism of injury was striking a hard object with a closed ®st in 17 patients, and a direct blow to the base of the ®fth metacarpal in ®ve. Initial radiographs identi®ed four Type A fractures, ten Type B fractures, six Type C fractures and two Type D fractures (Fig 1). The initial injury radiographs demonstrated an average of 15% (range, 0±60%) subluxation and an average of 2 mm of articular step o (range, 0±5 mm; Figs 1 and 2).
260
The average time of cast immobilization and clinical healing were both 5 weeks (range, 4±7 weeks). There were no complications of cast immobilization, such as skin breakdown and ®nger joint contractures. The average time to return to full duty (deployable military condition) in the 21 active duty patients was 6 weeks (range, 4±10 weeks). Average grip strength of the injured hand was 98% (range, 73%±119%) of the grip strength of the contralateral hand at follow-up and was not in¯uenced by fracture pattern (P=0.3), intraarticular step-o (P=0.7) or fracture subluxation (P=0.4). Thirteen patients reported an excellent result, seven a good result, one a fair result and one a poor result with respect to pain, function, disability and grip strength. Subjectively, eight of the 22 patients had intermittent pain, and one of these also complained of weakness, while another experienced intermittent tingling and stiness of the little ®nger. No patient was disabled or on disability at the time of follow up. The clinical outcome was not determined by the fracture pattern (P=0.8), intraarticular step-o (P=0.8), or fracture subluxation (P=0.7). Correlation of subjective outcome with grip strength of the injured hand approached statistical signi®cance (P=0.052). There were no nonunions or malunions but nine patients had mild arthrosis (Grade 1). There were no cases of more severe arthrosis and there was no statistical relationship between the presence of degenerative changes and fracture pattern (P=0.5), intraarticular stepo (P=0.7), fracture subluxation (P=0.8), grip strength (P=0.2), or subjective outcome (P=0.8). DISCUSSION Clement (1945) ®rst described an isolated intraarticular fracture of the base of the ®fth metacarpal. Since then multiple case reports and series have been published but the optimal treatment of these fractures remains uncertain (Bora and Didizian, 1974; Hagstrom, 1975; Hus and Curtis, 1970; Hunter and Cowen, 1970; KjaerPetersen et al., 1992; Lilling and Weinberg, 1979; Niechajev, 1985; Petrie and Lamb, 1974; SaÈlgeback et al., 1971). Striking a hard object with a closed ®st was the most frequent single cause of an intraarticular fracture of the base of the ®fth metacarpal in our, and others, series (Lilling and Weinberg, 1979; Niechajev, 1985). In most cases a force acting on the head of the metacarpal causes a subcapital fracture (metacarpal neck), but in some cases fracture at the metacarpal base occurs. Instability of intraarticular fractures of the ®fth metacarpal base is primarily due to the strong, unopposed proximal pull of the extensor carpi ulnaris which causes ulnar and dorsal subluxation of the main fracture fragment. The radial fragment at the base of the ®fth metacarpal is held in place by the sturdy interosseous metacarpal ligament
THE JOURNAL OF HAND SURGERY VOL. 25B No. 3 JUNE 2000
which connects the bases of the fourth and ®fth metacarpals. The ®rst comprehensive study to look exclusively at isolated intraarticular fractures of the base of the ®fth metacarpal was by Petrie and Lamb (1974). In a review of 19 cases treated conservatively with early active mobilization, they found minimal loss of grip strength and an average time o work of 3 weeks. Only one patient had signi®cant pain and they concluded that good results could be expected with early unrestricted mobilization. However, Bora and Didizian (1974) recognised decreased grip strength as the major functional disability after inadequate reduction of these fractures. In a retrospectively review of 25 cases they concluded that minimally displaced fractures are adequately treated with a molded cast, but fractures that are signi®cantly displaced are best treated by either closed reduction and percutaneous pinning or open reduction and internal ®xation. Grip strength was noted to be decreased in those which united with signi®cant displacement. Unfortunately, the authors failed to quantify their grip strength measurements and did not clearly de®ne ``signi®cant'' displacement. Niechajev (1985) performed a retrospective review of 23 fractures, which were either treated by closed reduction and percutaneous pinning or open reduction and internal ®xation. He reported ``good'' results based on the subjective functional recovery, the absence of persistent tenderness and the measurement of grip strength. KjaerPetersen and coworkers (1992) analysed a series of 64 intraarticular fractures of the base of the ®fth metacarpal with special emphasis on the method of treatment and the functional results. Both conservative and operative methods of treatment were used, and they reported that the alignment of 63% of the fractures was improved with open reduction and internal ®xation, compared with only 20% for those treated with closed reduction and casting. However, the quality of the fracture reduction did not in¯uence the outcome: nine of 20 patients treated conservatively had symptoms at follow-up compared to nine of 23 patients treated with pin ®xation. Despite these ®ndings, these authors recommended restoration of articular congruity and internal ®xation for displaced fractures. In contrast the present study has shown that closed reduction and castings is an adequate and reliable treatment method for intraarticular fractures of the base of the ®fth metacarpal. All fractures healed quickly (average, 5 weeks) and all active duty military patients returned to full duty status after an average of 6 weeks. Persistent symptoms at an average follow-up of 43 months were minimal and grip strength was equivalent to that of the uninvolved hand. Severe arthrosis was not observed, although mild arthrosis was noted in nine carpometacarpal joints. The presence or absence of these mild degenerative changes did not in¯uence outcome and all but one patient was satis®ed.
INTRAARTICULAR FRACTURES OF THE FIFTH METACARPAL BASE
We recognize that there are several limitations to this study. Selection bias towards less severe fracture patterns being treated conservatively may have existed, but our review of fracture patterns and fracture displacement suggests otherwise: most of our fractures had a signi®cant amount of intraarticular displacement and eight of the 22 fractures were comminuted. Additional limitations include the retrospective nature of this study and the relatively short follow-up period with respect to the development of osteoarthritis. Despite these limitations, we feel that our study demonstrates that closed treatment of isolated intraarticular fractures of the base of the ®fth metacarpal can be reliably treated with cast immobilization. References Bora FW, Didizian NH (1974). The treatment of injuries to the carpometacarpal joint of the little ®nger. Journal of Bone and Joint Surgery, 56A: 1459±1463. Clement BL (1945). Fracture±dislocation of the base of the ®fth metacarpal. A case report. Journal of Bone and Joint Surgery, 27A: 498±499. HagstroÈm P (1975). Fracture dislocation in the ulnar carpometacarpal joints. Open reduction and pinning ± a case report. Scandinavian Journal of Plastic and Reconstructive Surgery, 9: 249±251.
261 Hsu JD, Curtis RM (1970). Carpometacarpal dislocations on the ulnar side of the hand. Journal of Bone and Joint Surgery, 52A: 927±930. Hunter JM, Cowen NJ (1970). Fifth metacarpal fractures in a compensation clinic population. A report on one hundred and thirty-three cases. Journal of Bone and Joint Surgery, 52A: 1159±1165. Kjaer Petersen K, Jurik AG, Petersen LK (1992). Intra-articular fractures at the base of the ®fth metacarpal. A clinical and radiographical study of 64: cases. Journal of Hand Surgery, 17B: 144±147. Knirk JL, Jupiter JB (1986). Intra-articular fractures of the distal end of the radius in young adults. Journal of Bone and Joint Surgery, 68A: 647±659. Lilling M, Weinberg H (1979). The mechanism of dorsal fracture dislocation of the ®fth carpometacarpal joint. Journal of Hand Surgery, 4A: 340±342. Niechajev I (1985). Dislocated intra-articular fractures of the base of the ®fth metacarpal: a clinical study of 23 patients. Plastics and Reconstructive Surgery, 75: 406±410. Petrie PWR, Lamb DW (1974). Fracture subluxation of the base of the ®fth metacarpal. The Hand, 6: 82±86. SaÈlgeback S, Eiken O, Carstam N, Ohlsson NM (1971). A study of Bennett's fracture. Special reference to ®xation by percutaneous pinning. Scandinavian Journal of Plastic and Reconstructive Surgery, 5: 142±148. Shephard E, Solomon DJ (1960). Carpo-metacarpal dislocation. Report of four cases. Journal of Bone and Joint Surgery, 42B: 772±777.
Received: 23 November 1999 Accepted after revision: 24 March 2000 Alexander Y. Shin MD, Department of Orthopaedic Surgery, Naval Medical Center San Diego, San Diego, CA 92134-500, USA. # 2000 The British Society for Surgery of the Hand DOI: 10.1054/jhsb.2000.0413, available online at http://www.idealibrary.com on