1 Introduction

Intramedullary nail (IMN) is generally accepted as the standard treatment for femoral shaft fracture.¹ Infra-isthmic femoral fracture was considered as location for potentially femoral non-union, regarding to widen medullary canal resulting in decrease fixation stability by IMN² Without proper fracture healing in appropriate time, implant may reach the fatigue failure and finally bent or broken. These complications are rare but challenging and various surgical technique for implant removal had been reported.^3–23

We reported a patient who got the infra-isthmic femoral fracture treated with open reduction internal fixation (ORIF) with IMN. The distal part of the nail was broken during 6 months of follow up. Without proper intervention, the remaining proximal nail was subsequently angulated resulting in complex deformity. He was diagnosed as hypertrophic nonunion with sagittal plane deformity with concomitant bent and broken intramedullary nail. The operation was planned for corrective osteotomy, removal of previous nail then internal fixation with IMN and plate augmentation. The fracture healed uneventfully after correction. This combination of rare fixation failure, concomitant bent and broken nail, was first described and methods of management was reviewed.

2 Case

A 23-year-old male involved in a motorcycle accident sustained a closed distal shaft femoral fracture and was treated with an open reduction internal fixation with IMN. During the follow-up, he was allowed to progress weight bearing, as the radiograph revealed progressive fracture healing. Unfortunately, the nail was broken at the distal locking screw hole. He was advised for revision surgery, but he refused the treatment. Then the limb was gradually deformed and increased angulation of the remaining proximal part of the nail (Fig. 1). The physical examination revealed the anterolateral deformity of the distal thigh. Affected hip range of motion was excessive external rotation compared to the normal side (Fig. 2). Both knee and ankle motion were normal. The neurovascular status was intact. No sinus drainage or any evidence of suspected infection was observed. The radiograph revealed hypertrophic non-union with sagittal plane deformity and 30° anterior-apex angulation of the nail in the sagittal plane at the nonunion area with broken distal part.

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Fig. 1 Pre-operative radiographs; a) initial injury, b) immediate post-operative after ORIF with IMN, c) long standing radiographs showed sagittal plane deformity with bent and broken nail, d) CT rotation profile revealed externally malrotation of the affected side.

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Fig. 2 Pre-operative range of motion of the affected side; a, b) anterolateral bowing of the distal thigh with normal range of motion of the knee, c) excessive external rotation of the affected side.

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The pre-operative planning was prepared for closed wedge osteotomy to correct the sagittal plane deformity, de-rotation to correct external rotation malalignment and revision fixation with IMN and plate augmentation to achieve adequate stability. Iliac bone grafting was not considered regarding to hypertrophic-type nonunion (Fig. 3).

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Fig. 3 The surgical steps of planning; a) calculation of magnitude of deformity and plan for anterior close-wedge, posterior open-wedge osteotomy, b) partial weakening of bent nail by metal carbide high speed blur through the osteotomy window, c) manual straightening of bent nail as much as possible and remove with the standard extraction device, d-e) fitted T-reamer with distal part before remove the distal locking screws, f) direct reduction and provisionally plate fixation, g) antegrade reamed interlocking nail was finally done.

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Under spinal anesthesia, patient in supine position, the lateral subvastus approach was performed to expose the nonunion site. Anterior bone wedge was removed as planned, then the nail was visible at the apex of angulation through the osteotomy window. Partial resection of the nail was done using metal cutting high speed blur. During cutting, metal debris were carefully collected with sterile lubricant around the cutting site, irrigated and suction. The nail then was manually straightened as possible and removed with extraction device connected to the tip of the nail in standard maneuver. For the remaining distal part, T-reamer was inserted snugly fit to the nail through the bone window, then remove the distal locking screws and distal part of the nail. The distal fragment was internally de-rotated and reduced to correct alignment and provisionally fixed with small 3.5 locking compression plate. Local bone grafting was packed into any visible gap in the osteotomy site. The femoral canal was then reamed to 2 mm greater than the diameter of the original nail and a new nail was inserted. Interlocking screws was inserted using the fluoroscope (Fig. 4). Post-operative radiograph showed improved alignment, uneventful healing (Fig. 5) and satisfactory functional outcome (Fig. 6).

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Fig. 4 The steps of surgery; a) K-wires were inserted in calculated angle for anterior closing wedge corrective osteotomy, b) bony wedge removal, c) visible nail through the osteotomy window, d) partial nail weakening was done, manual straightening then nail was removed proximally, e) remaining distal part was removed by T-reamer technique, f) derotational correction and provisional fixation with small LCP, g) filled osteotomy site with local bone graft, h) reaming for IMN.

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Fig. 5 The radiographs showed a) postoperative alignment in coronal and sagittal plane, b) uneventful fracture healing after surgery at 1 year, c) correction of malrotation.

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Fig. 6 The post-operative functional outcome.

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3 Discussion

Femoral nonunion is not uncommon after intramedullary nailing and the infra-isthmic location was considered as risk factor for nonunion.² The shorter length of distal fragment and the widening of the medullary canal resulting in inadequate stability. Additional fixation was suggested to improve stability in non-isthmic location.²⁴ Our case demonstrated this healing problem regarding to inadequate stability, larger diameter of the nail and plate augmentation was considered to improve the construct stiffness.

Several bent nail removal surgical techniques have been reported as shown in the Table 1. Most of the techniques shared similarity and can be simplified into 4 categories: 1) standard removal without intervention 2) in situ straightening 3) partial weakening and 4) complete transection.

Bent nail can be removed in standard fashion without any intervention if the angle of nail deformity was small. It was assumed that the intramedullary of the bone will rebending the nail to its original shape during extraction. Yip et al.²⁵ and Kose et al.¹⁴ suggested this technique was feasible if the angulation was less than 15–20°. However, this method depends on the flexibility of the nail and the quality of the bone. The hollow, thin, titanium nail was feasible for this method, otherwise this will add more iatrogenic fracture to the bone while forceful extraction.

In situ straightening is another method in more angulated situation. This can also be done in closed or open approach. Patterson et al.¹⁰ described using the perineal post as the fulcrum to create reduction force. This method can be tried as the first reduction attempt because it does not need any special equipment but need to be cautious with excessive reduction force. The soft tissue complication at the fulcrum area or ligament injury of the adjacent joint while levering with excessive force might occur, as well as additional fracture. This method can be successful in relatively flexible nail such as Kuntcher nail.¹⁵ Kritsaneephiboon et al.¹³ described in situ straightening with plate and clamps assisted using the open approach. This can avoid the soft tissue injury from closed technique, but it needs more surgical exposure, soft tissue injury, special implant and straight plate application might not be easy to hold with deformed bone. This cannot be done with high strength nail.

Partial weakening seems to be easier, simpler, and the most popular method. The objective is too weakening the nail by drilling or partially cutting, make it able to straighten before or during extraction. This can be done through the percutaneous method⁵ or open through the fracture site.^6,9,11,12,14 Most of the studies using the metal high speed drill or blur able to cut the steel. Apivatthakakul et al. (8) described a closed percutaneous controlled weakening of the nail by a single drill hole at the apex of angulation with minimal soft tissue injury and straightening the nail before removal. Because of the need of corrective osteotomy, we decided for open wedge osteotomy at the apex then remove the osteotomy wedge to expose the bent nail through the osteotomy window. Partial weakening was performed then manually straighten as possible before nail removal. If partially sectioning of the nail cannot allow for nail straightening, complete cutting the nail is considered then removed both proximal and distal nail through the fracture site^8,9,11 or more extensive exposure such as extended longitudinal osteotomy.²³

Retrieving the remaining distal part that buried inside the intramedullary canal is also challenging. Several options and modifications have been reported with satisfactory outcomes as shown in Table 2. Despite the various techniques were proposed by each author, we could simplify into 3 categories: proximally fitted, distally fitted and retrograde retrieval method.

The important details necessary for pre-operative including design of the nail, solid or cannulated nail, the nail diameter, location of broken implant and status of fracture healing. These all influenced the appropriate method of removal. Proximally fitted method can be done to fit the proximal end of the remaining distal part of the broken nail with T-reamer,²² elastic nail²¹ or smaller-size nail.¹⁶ One distal screw needs to be maintained while impact the instrument to fit proximal end of the broken part. After it jammed into single unit, back slap was done to extract the distal part proximally. Pongsamakthai et al. described using the appropriate size of T-reamer to engage the proximal aspect of the broken part with successful outcome. This is a simple instrument which available in the operating room. Kim et al.²¹ demonstrated using the smaller elastic Nancy nail with grounded surface to achieve firm attachment with the distal fragment. Sivananthan et al.¹⁶ demonstrated impacting the 3-mm smaller diameter nail into the remaining distal part and removed with standard extractor. The proximal reaming with 2 size larger diameter than the original nail to enlarge proximal canal, facilitate the distal part removal, was recommended.^16,22

Distally fitted method is done by insertion instrument through the hollow nail then create interference fit and make it jam distally with multiple guided wire or modifications,¹⁸ hook equipment,⁷ flexible nail³ or screw through the distal locking screw hole¹⁷ was also described. They shared the same principle by press fitting the remaining part with any instrument. This method is only possible when the nail has enough area to pass the described instrument through the distal end. Riansuwan et al.¹⁸ demonstrated using bent ball-tipped guide wire act as the hook to capture the end of the distal part. They twisted two guide wire to create the secure handle between the guide wires and implant before extraction. In case of unable to fit the distal part or the distal part was in very distal location, retrograde retrieval method is alternative,^19,20 either by pull the distal fragment into the knee joint or push it back from the knee toward proximal direction. The main disadvantage of this technique is the risk of violation of the knee joint. In our case, we tried to use the multiple guide wire technique as the first method but encountered difficulty to insert the guide wire through the distal part due to the previous deformity. Then the proximally fitted method was applied through the osteotomy bone window with T-reamer and extracted the distally part successfully.²²

Based on our study, we recommend following these learning points when the pre-operative planning was prepared for bent or broken intramedullary nail removal to prevent the unexpected situation.-Early revision of delayed union with broken implant can prevent complex implant-related complications.-Complex deformity needs meticulous pre-operative planning in 3-dimensions.-Drilling or partially cut of the nail at the apex of the deformity weaken the nail and straightening the nail is possible.-Removal of the distal part of the broken nail can be done using the T reamer technique impaction.-No single technique fits all cases. The surgeon should know various techniques, from simple to complex, for dealing with surprising situations.

In summary, our case demonstration pointed out the consequence of untreated complication of intramedullary fixation in femoral fracture resulting in complex situation. We reported the concomitant bent and broken nail with sagittal plane deformity with excellent outcome after surgical correction. This report also reviewed the armamentarium to manage both bent and broken intramedullary nail. There is no one option fits all solution. It is utmost importance to understand the principle and techniques for encountered any unexpected situation.

Funding

No funds have been received for this study.

Informed consent

Informed consent was obtained for the patient.

Author contributions

CJ and PR were involved in drafting and revising the manuscript for content, including the medical writing for the content and review literatures. PR was drawing the illustrations. TA involved in revising the manuscript.

Ethical approval

This study has been approved by the ethical committees of Lerdsin Hospital in accordance with the declaration of Helsinki.