Factors influencing functional outcomes after distal tibia shaft fractures

Surgical treatment of displaced distal tibia fractures yields reliable results with either plate or nail fixation. Comparative studies suggest more malalignment and nonunions with nails. Some studies have reported knee pain after tibial nailing. However, plates may be associated with soft tissue complications, such as infections or wound-healing problems. The purpose of this study was to assess functional outcomes after distal tibia shaft fractures treated with a plate or a nail. We hypothesized that tibial nails would be associated with more knee pain and that plates would be associated with pain from implant prominence, each of which would adversely affect functional outcome scores.

Randomized prospective study.

Level 1 trauma center.

One hundred four patients with extra-articular distal tibia shaft fractures (OTA 42), mean age of 38 years (range, 18-95), and mean Injury Severity Score of 14.3 (range, 9-50).

Patients were randomized to treatment with a reamed intramedullary nail (n = 56) or standard large fragment medial plate (n = 48).

Ability to work was evaluated after a minimum of 12 months, with mean of 22 months. Foot Function Index (FFI) and Musculoskeletal Function Assessment (MFA) questionnaires were completed.

Mean MFA was 27.5, and mean total FFI was 0.26; P < 0.0001 versus an uninjured reference population. Sixty-one of 64 patients (95%) employed at the time of injury had returned to work, although 31% had modified their work duties because of injury. Three patients were unable to find work. None reported unemployment secondary to their tibial fracture. Forty percent of all patients described some persistent ankle pain, and 31% had knee pain after nailing, versus 32% and 22%, respectively after plating. Both knee and ankle pain were present in 27% with nails and 15% with plates (P = 0.08), and rates of implant removal were similar after nails versus plates. Patients with malunion ≥5 degrees were more likely to report knee or ankle pain (36% vs 20%, P < 0.05). Except 1 patient with knee pain when kneeling, none reported modifying activity because of persistent knee or ankle pain, although knee and ankle pain were more frequent in the unemployed (P = 0.03). Unemployed patients requested implant removal more frequently (24% vs 9.2%, P = 0.07) and continued to report pain afterward. Although FFI and MFA scores were not related to plate or nail fixation, open fracture, fracture pattern, multiple injuries, Injury Severity Score, or age, both MFA and FFI scores were worse when knee pain or ankle pain was present (all Ps < 0.004) and in patients who remained unemployed (P < 0.0001). All 4 patients with work-related injuries had returned to employment but had worse FFI scores (P = 0.01).

Mean MFA and FFI scores suggest substantial residual dysfunction after distal tibia fractures when compared with an uninjured population. Mild ankle or knee pain was reported frequently after plate or nail fixation but was not limiting to activity in most. Angular malunion was associated with both knee and ankle pain, and there was a trend toward more patients with knee and ankle pain after tibial nailing. No patients reported unemployment because of their tibia fracture, but unemployed people described knee and ankle pain more frequently and had the worst functional outcome scores.