Intramedullary nailing is the preferred treatment of most femoral shaft fractures.5,6,13 After fracture consolidation, it is unclear whether the implant should be removed. During the past decades, hardware removal was considered to be a routine procedure after fracture healing.7,9 Patients with persisting pain after femoral nailing might improve after hardware removal.12 The recommended interval for nail removal after implantation is 24 months.9 Various authors have reported complications after nail removal, such as wound healing problems,1,4,8 and have recommended removal of femoral nails only for symptomatic patients.8
Although wound healing problems may extend the length of hospital stay, they rarely cause long-term problems. The question about the long-term outcome after femoral nail removal is not sufficiently addressed in the literature.1,4,8,12 The main goal of our study was to evaluate whether patients who had been asymptomatic before hardware removal might become symptomatic with pain or discomfort after femoral nail removal. There are two reports in the literature, which focus on factors that influence operation time and the incidence of postoperative soft tissue problems. Therefore, we analyzed the influences of nail depth, presence of an end-cap, type of nail, surgeon’s experience, interval to nail removal, ossification grade, and number of locking screws on the operation time. Operation time, surgeon’s experience, nail depth, and grade of heterotopic ossification were tested with postoperative wound complication as the dependent variable.
MATERIALS AND METHODS
An electronic database search and manual review of patients’ charts were done to identify patients who had removal of an intramedullary femoral nail between January 1, 1990 and March 31, 1999 in our level one trauma center. The inclusion criteria were implantation of an antegrade intramedullary femoral nail at our institution and removal of the nail after fracture consolidation. Medical records and radiographs were evaluated retrospectively to determine demographic data, type of implant, size of implant, presence of an end-cap, number of locking screws, interval between nail insertion and removal, broken implants, previous locking screw removal, additional implant removal, indications for nail removal, type of anesthesia, operating position, surgical approach, qualification of surgeon, time of surgery (incision to closed wound), use and duration of image intensifier, intraoperative problems, intraoperative complications, incomplete implant removal, postoperative complications, and length of hospital stay. All fractures were classified according to the AO/ASIF classification.10 The femur was divided in sixths for localization. The nail depth was assessed by the most recent AP radiograph. The depth was defined as the distance between the end of the nail and the cranial cortex of the femoral neck just medial to the nail. A negative value indicates protrusion of the nail. Heterotopic ossifications around the hip were classified according to Brooker et al.2
All radiographic classifications and measurements were done by one of us (TG). The patients were contacted by telephone by one of the investigators (AMH). The interview focused on preoperative and postoperative pain or discomfort. All patients were asked two standard questions. First, the patient was asked if there had been any pain before nail removal. If the answer to the first question was yes, the second question was whether these complaints subsided, improved, persisted, or got worse. If the answer to the first question was no, the second question was whether pain or discomfort had occurred since nail removal.
The data were evaluated by a professional statistician using SPSS 11.5 (SPSS Inc, Chicago, IL). Pearson’s correlation, one-way ANOVA, Kruskal-Wallis test, Pearson’s chi square test, and Mann-Whitney U test were used for statistical analyses. A p value < 0.05 was considered significant. Correlation values < 0.25 indicated a weak correlation; between 0.25 and 0.5, a mild correlation; between 0.5 and 0.75, a moderate correlation; and > 0.75 indicated a high correlation.
The influences of nail depth, presence of an end-cap, type of nail, surgeon’s experience, interval to nail removal, ossification grade, and number of locking screws on the operation time were analyzed. Operation time, surgeon’s experience, nail depth, and ossification also were tested with postoperative wound complication as the dependent variable.
One hundred forty-nine patients who met the inclusion criteria were identified. Fifteen patients had bilateral nail removal. One hundred sixty-four femoral nails were removed. Ninety-three nails (57%) were on the left side and 71 nails (43%) were on the right side. The average age of the patients was 29 years (range, 17–80 years). One hundred twelve (68%) of the nails were removed in male patients and 52 (32%) were removed in female patients. One hundred twenty-eight fractures (78%) were localized in the middle of the femur. Thirty-four radiographs of the initial injury were not available preventing AO/ASIF fracture classification. Among the remaining 130 fractures, 42 fractures were classified as Type A, 68 fractures were classified as Type B, and 20 fractures were classified as Type C. The leading fracture type was 32-B3 (n = 35). Most patients (n = 89/108) had routine removal on advice of the treating surgeon. Ten patients (9%), all asymptomatic, wanted nail removal. In eight patients (7%), pain was the indication for removal and in one patient (1%) the nail was removed because of restriction of motion. The average time between implantation and removal of the femoral nail was 27 months (range, 8–82 months). The indication for nail removal could be evaluated retrospectively in 108 patients (72%). The most common nail length was 400 mm (n = 45) and the most common diameter was 11 mm (n = 44). The following nail types were removed: 84 (51%) Unreamed Femoral Nails (UFN, Mathys, Bochum, Germany), 53 (32%) AO-Universal-Nails (AUN, Mathys), 19 (12%) Claw-Nails (CN, Mathys), and eight (5%) AO-Classic Nails (ACN, Mathys). The UFN was the only solid and only Ti nail. The CN was interlocked with special claws inserted from the interior of the nail. The ACN could not be interlocked. The UFN and the CN could be used with an end-cap to prevent bony ingrowth into the threaded end, and to facilitate insertion of the extraction device. An end-cap was used in 69 (67%) of 103 nails (15/19 CN; 54/84 UFN). The number of interlocking screws removed depended on the nail used and number of crosslocks inserted initially. In the AUN group locking with one proximal and two distal screws was the most common configuration (n = 30/53; 57%). Seven nails (13%) had no interlocking, four (8%) had one screw, six (11%) had two screws, and another six (11%) had four screws. In the UFN group most nails were statically locked with two proximal and two distal screws (n = 62/84; 74%). Twenty nails (24%) had three screws and two nails (2%) had only two screws. Of 164 nails, only one AUN (1%) was broken. Screw breakage was reported in nine patients (5%). Three UFN had both distal screws broken. An additional four UFN and one AUN had one broken distal screw. One UFN had proximal screw breakage. Ten patients (6%) had one or more locking screws removed before removal of the nail. The nail depth was measured in 148 of 164 femurs. The radiographs of the remaining 16 femurs did not show the end of the nail. Ninety-nine (67%) nails showed some protrusion. In nine femurs (6%) the end of the nail fit exactly with the cranial cortex of the femoral neck. Forty nails (27%) caused intrusion. The maximal depth was 45 mm and the maximal protrusion 35 mm. In 143 femurs (87%) the most recent radiograph allowed classification of heterotopic ossifications about the hip. In 57 hips (40%) no heterotopic ossifications were recorded. Forty-four patients (31%) had Grade 1 heterotopic ossifications, 32 (22%) had Grade 2 heterotopic ossifications, nine (6%) had Grade 3 heterotopic ossifications, and one (1%) had Grade 4 heterotopic ossifications. An image intensifier was used in 47 removals (29%). The average radiation time was 91 seconds with a median of 54 seconds (range, 2–556 seconds). Only seven nails (4%) were removed with the patient under spinal anesthesia. The other procedures were done with the patient under general anesthesia. One hundred thirty-three nails (81%) were removed with the patient in the supine position, 20 (12%) with the patient in the lateral position; and in 11 patients (7%) the position could not be evaluated. The preexisting proximal approach was used in all but one removal. In this patient, a second proximal incision had to be made to access the piriformis fossa. In 10 femurs (6%), the proximal incision had to be extended. The operations were done by trauma interns (n = 51/164; 31%), residents in training for general surgery (n = 72; 44%), and board certified trauma surgeons (n = 41; 25%). Several intraoperative problems were recorded. With the AUN, prolonged removal time with a fractured nail occurred in one patient. With the CN, intraoperative breakage of one claw occurred. The claw had to be left in situ. In the same patient, the extraction device could not be connected to the nail end because of a damaged thread. Therefore, the nail end was cut and two holes were drilled into the nail to lock a hook for extraction. With the UFN, breakage of one nail at the most distal interlocking hole occurred during extraction. The nail tip had to be left in situ. In another patient, one broken screw could not be removed completely. In one patient, an osteotomy of the trochanter was necessary to get access to the nail end. In two patients, the screw heads had to be exposed for removal. One patient had a grand mal seizure in the recovery room. Overall, in two patients the implant could not be removed completely (one nail tip, one screw tip). In patients who had an isolated nail removal, the average length of hospital stay was 7.8 days (range, 4–18 days). The average length of hospital stay decreased from 11 days in 1993 to 6 days between 1997 and 1999. In patients with bilateral femoral nail removal, the average length of hospital stay was 14 days (range, 6–34 days).
Neither the interval between nail implantation and nail removal nor the use of an end-cap significantly influenced the operation time (Table 1). The surgeon’s qualification (p = 0.041) and nail depth (p < 0.0001) were the only variables that influenced operation time. In 60 patients (37%), additional procedures (mainly hardware removal) were done. Only the 104 patients with isolated unilateral nail removal were used for statistical analysis of the operating time. The average operating time was 88 minutes (range, 15–230 minutes). To evaluate the influence of nail type on operating time, only nails with one proximal and two distal locking screws were used for statistical analysis. The board certified trauma surgeons (74 minutes) were significantly faster (p = 0.041, Kruskal-Wallis test) than the interns (87 minutes) or the general surgery residents (95 minutes). The surgeon’s qualification had a significantly higher (p = 0.048, one-way ANOVA) influence on the operation time with nail depth as a covariant.
Neither the operation time (p = 0.396; Mann-Whitney test), nail depth (p = 0.900; Mann-Whitney test), surgeon’s qualification (p = 0.790; Pearson’s chi square test), or the grade of heterotopic ossification (p = 0.907; Pearson’s chi square test) significantly influenced the incidence of wound healing problems. Eighteen patients (11%) experienced postoperative hematoma or seroma. In 12 patients (7%), a secondary procedure was necessary. In 11 patients (7%), one or more percutaneous aspirations were necessary. One of these 11 patients required a second drain to be placed while under local anesthesia. One patient had surgery under general anesthesia for evacuation of the hematoma. No infections were reported.
Local complaints and discomfort increased in 13% of patients who were available for the followup interview. Twenty percent of the previously asymptomatic patients had long-term complaints after nail removal (Table 2). One hundred nine patients (73%) could be contacted by telephone. Two patients were lost to followup because of death; a current address could not be obtained for 40 patients; and eight patients did not return several phone calls during a 4-month period. The average time between nail removal and our interview was 6.3 years (range, 2–11 years). Fifty-eight patients reported local pain or discomfort before nail removal. Forty-five of these patients (78%) reported some or complete relief of pain after nail removal. Nine patients (16%) reported no change, and four patients (7%) reported increased pain after surgery. Fifty-one patients had no local complaints before the operation. Ten of these patients (20%) reported local complaints or discomfort after nail removal. Of 109 patients who were available for followup, 50 patients (46%) did not benefit from nail removal and local complaints and discomfort worsened in 14 patients (13%). None of the 109 patients had a refracture.
This study was done to suggest treatment guidelines for femoral nail removal in asymptomatic patients. We assumed that femoral nail removal is associated with complications and is able to cause long-term complaints.
This study has some shortcomings. It is retrospective and has no control group. The radiologic analysis was done by one observer and we did not test the intraobserver reliability. In addition, the reliability of the telephone interview was not evaluated. A followup would have been more adequate but was not done because of the very small response. Most patients had no or minor complaints and refused to return to the hospital. The Lower Limb Questionnaire (American Academy of Surgeons, Outcomes Data Collection Questionnaires, which contains parts of the Short-Form-36 (SF-36) Health Status Questionnaire) would be appropriate for patient evaluation.3a It might not be difficult to get the correct answers for the status at the followup interview, but for many patients the interval from surgery to followup seemed too long to remember every detail of their preoperative status. The same is true for the visual analog scale. We tried to keep the interview as simple as possible. We asked about pain and complaints before surgery and at followup, and whether their symptoms improved or were exacerbated by surgery. Nevertheless, we think that we have a reliable database for our conclusions.
Our findings regarding factors that influence the operation time (Table 1) conformed to previous reports in the literature (Table 3). The operation time was not shortened if an end-cap was used on implantation. We think that removal of the end-cap might be as time consuming as removal of ingrown bone. Therefore, we do not recommend using an end-cap on initial insertion. An image intensifier was required in more than 25% of the procedures. The radiation exposure in these patients was relatively high. An image intensifier may be necessary to locate the correct position of the nail end. The operating team should take this into account during preoperative planning.
In accordance with the literature (Table 3), the number of intraoperative complications in our series was low. The number of postoperative soft tissue problems was comparable to numbers cited in previous reports (Table 3). Soft tissue problems can lead to prolonged hospital stay with or without reoperation. Although the hospitalization time decreased during the last years of the observation, it was high compared with the hospitalization times in other studies.4,8 We attribute this finding to differences between the health systems in North America and Middle Europe. Boerger et al1 reported an average of 11 days of sick leave. Data on the postoperative use of crutches, early postoperative pain, and the abductor strength were not available.
Another important finding was that a longer interval between implantation and removal of the nail does not influence operation time and incidence of postoperative complications. Therefore, removal can be done at any date, and routine early removal to avoid problems on late removal is not advised.
In our series, most patients were advised to have hardware removal as a routine procedure. Nevertheless, ½ of the patients felt some pain or discomfort in the affected thigh. Most of our symptomatic patients reported some or complete relief of their symptoms after nail removal. In a study by Toms et al,12 using a matched-pair analysis, the SF-36 was higher in patients having femoral nail removal, but their findings were not significant. Hardware removal still is indicated in symptomatic patients. However, numerous patients experienced aggravation of their symptoms. Ostrum et al11 reported improvement of distal thigh pain by isolated removal of the interlocking screws in retrograde nails. We think these findings can be applied to antegrade nailing, and recommend that isolated screw removal under local anesthesia be considered before removing the entire nail.
Very active patients with an intramedullary nail may be asymptomatic. In a small series focusing on professional rugby players with remaining metal implants, patients with nails on the lower extremity had no problems when playing.3 Twenty percent of the previously asymptomatic patients became symptomatic after femoral nail removal. Previous authors have suggested that nail removal should be done only in symptomatic patients.1,4,8 However, our finding is a more powerful argument against routine removal of femoral nails in asymptomatic patients. Only symptomatic patients should be considered for nail removal unless an asymptomatic patient insists on nail removal. All patients must be informed that soft tissue problems resulting in prolonged hospitalization or reoperation may occur, that their symptoms may get worse, and that new pain may arise.
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