Session X - Upper Extremity

Functional Outcome after Open Reduction and Internal Fixation of Both-Bone Forearm Fractures

Frank Tull, MD; Joseph Borrelli, Jr., MD; Dawn Ray, RN; William M. Ricci, MD; Washington University School of Medicine, St. Louis, Missouri, USA

Purpose: Both-bone forearm fractures (BBFF) are routinely treated with open reduction internal fixation (ORIF) and, although uncomplicated union is expected, the morbidity that arises from such an injury and treatment is largely unknown. Therefore, the purpose of this investigation was to critically assess clinical, radiographic, and functional outcomes of patients treated for displaced fractures of the radial and ulnar shafts with ORIF and early motion and rehabilitation.

Methods: Between May, 1996 and December, 2000, 22 consecutive patients with BBFF underwent ORIF with LC-DC plates through separate approaches. The postoperative protocol included short-term immobilization, active assisted elbow, wrist, and forearm range-of-motion (ROM) exercise on average of 8 days (range, 5 to 12) postoperatively. Muscle strengthening was initiated on average at 6 weeks (range, 4 to 7) after the operation. Twelve men and 10 women with an average age of 37 years (range, 22 to 56) comprised the patient population. Fractures were classified according to the OTA system: 6 type 22-A, 14 type 22-B, and 2 type 22-C. Follow-up averaged 25 months (range, 14 to 60). Each patient was assessed clinically for forearm ROM, muscle strength (grip, pinch), and upper extremity dexterity by using the Manual Dexterity Test. Radiographs were used to assess healing, maximum radial bow, and for comparison with the contralateral forearm. Functional outcome was assesed with the MFA and DASH questionnaires.

Results: Pronation of the affected forearm was reduced (P<0.05) when compared with the unaffected forearm, as was supination. Wrist flexion and extension results were the same for both, as was key pinch strength. Grip strength of the affected arm was reduced (P<0.05) relative to the unaffected forearm. (Tables 1 and 2)

Table 1	Affected	Range	Unaffected	Range	P values
Forearm pronation	74°	45-110°	88°	74-110°	P = 0.02
Forearm supination	89°	56-115°	93°	75-107°	P = 0.24
Wrist flexion	59°	45-75°	60°	55-65°	P = 0.85
Wrist extension	68°	57-86°	70°	55-80°	P = 0.46

Table 1. Average measured range of motion of the affected and unaffected forearms and wrists. A paired t-test was used to determine statistically significant differences in range of motion.

Table 2	Affected	Range	Unaffected	Range	P values
Grip strength	39 lbs.	20-58 lbs.	47 lbs.	28-68 lbs.	P = 0.005
Key pinch strength	22 lbs.	13-30 lbs.	23 lbs.	15-30 lbs.	P = 0.47

Table 2. Grip and key pinch strength for the affected and unaffected forearms. A paired t-test was used to detect statistically significant differences in strength.

The average MFA score was 22 (range, 6 to 35), with patients losing points in the "hand and fine motor skills," "housework," "employment and work," and "leisure and recreational activities" domains. Results of the DASH instrument demonstrated relatively high patient satisfaction, and, for the most part, patients had returned to their premorbid function with some limitations. Pain and impairment scores were moderately low. Radiographically, all fractures healed, with an average maximum radial bow of 16 mm (range, 14.5 to 16.5 mm), which was typically located 60% of the length from the bicipital tuberosity.

Discussion: Anatomic reduction and stable internal fixation is the standard of care for BBFF in adults. When combined with early mobilization and muscle strengthening, good results are expected. However, assessment after treatment has traditionally focused on clinical or surgeon-defined measures of technical success rather than on functional outcome. We combined an assessment of technical success (restoration of radial bow) with functional outcome in this patient population to determine their true outcome. Forearm pronation and grip strength was most significantly affected. These limitations correlated with physical limitations uncovered by the MDT. However, because the MFA and DASH scores were good, this finding suggests that the patients have learned to accommodate for these losses without being cognizant of them. The results of this study support the current treatment protocol for BBFF. However, increased attention should be paid to restoration of forearm pronation and strength to maximize function. A combination of objective and subjective means of assessing outcome should be used to fully assess outcome.