[Avascular femur head necrosis as severe complication after femoral intramedullary nailing in children and adolescents]

Osteonecrosis of the femoral head: diagnosis and classification systems

Osteonecrosis of femoral head is a rare but disabling condition that usually results in progressive femoral head collapse and secondary arthritis necessitating total hip arthroplasty if not treated appropriately in early stages. However, early diagnosis is challenging as the onset of disease is insidious and the symptoms and signs are usually minimal and nonspecific until it becomes advanced. Of several diagnostic modalities, magnetic resonance imaging (MRI) is considered the imaging method of choice with the highest sensitivity and specificity, while detection of potential risk factors is very important as well. Many investigators have developed several different classification systems; however, there still is controversy regarding the optimal classification system. Diagnostic methods and the evolution of different classification systems will be reviewed in this paper.

Functional outcome after antegrade femoral nailing: a comparison of trochanteric fossa versus tip of greater trochanter entry point

OBJECTIVES

This study was performed to explore the relationship between entry point-related soft tissue damage in antegrade femoral nailing and the functional outcome in patients with a proximal third femoral shaft fracture.

DESIGN

Retrospective clinical trial.

SETTING

Level I university trauma center.

PATIENTS

Seventeen patients with a high femoral shaft fracture treated with an antegrade femoral nail joined the study.

INTERVENTION

Nine patients with an Unreamed Femoral Nail (UFN; Synthes, Bettlach, Switzerland) inserted at the trochanteric fossa and eight patients with a long Proximal Femoral Nail (PFN; Synthes) inserted at the tip of the greater trochanter.

MAIN OUTCOME MEASUREMENTS

Pain, gait, nerve, and muscle function along with endurance.

RESULTS

Five patients with a UFN had a positive Trendelenburg sign and a reinnervated superior gluteal nerve after initial injury of the nerve at operation. None of these findings occurred in the long PFN group (P = 0.01). Isokinetic measurements showed diminished abduction as well as external rotator function in the UFN group rather than in the long PFN group. Leg endurance was significantly lower in patients with a UFN.

CONCLUSIONS

Compared with the trochanteric fossa, femoral nailing through the greater trochanter tip may decrease the risk of damage to the superior gluteal nerve and intraoperative damage to the muscular apparatus of the hip region, resulting in some improved muscle function. Therefore, a lateral entry point may be a rational alternative for conventional nailing through the trochanteric fossa.

Intramedullary femoral nailing through the trochanteric fossa versus greater trochanter tip: a randomized controlled study with in-depth functional outcome results

PURPOSE

In a level 1 university trauma center, an explorative randomized controlled study was performed to compare soft tissue damage and functional outcome after antegrade femoral nailing through a trochanteric fossa (also known as piriform fossa) entry point to a greater trochanter entry point in patients with a femoral shaft fracture.

MATERIALS AND METHODS

Nineteen patients were enrolled and randomly assigned to two nail insertion groups; ten patients were treated with an Unreamed Femoral Nail(®) (UFN, Synthes(®), Solothurn, Switzerland) inserted at the trochanteric fossa and nine patients were treated with an Antegrade Femoral Nail(®) (AFN, Synthes(®), Solothurn, Switzerland) inserted at the tip of the greater trochanter. The main outcome measures were pain, gait, nerve and muscle function, along with endurance. Magnetic resonance imaging (MRI), electromyography (EMG), and Cybex isokinetic testings were performed at, respectively, 2 and 6 weeks and at a minimum of 12 months after surgery.

RESULTS

The MRI and EMG showed, in both groups, signs of iatrogenic abductor musculature lesions (four in the UFN group and four in the AFN group) and superior gluteal nerve injury (five in the UFN group and four in the AFN group). The isokinetic measurements and the patient-reported outcomes showed moderate reduction in abduction strength and endurance, as well as functional impairment with slight to moderate interference with daily life in both groups, with no appreciable differences between the groups.

CONCLUSIONS

Anatomical localization of the entry point seems to be important for per-operative soft tissue damage and subsequent functional impairment. However, the results of this study did not show appreciable differences between femoral nailing through the greater trochanter tip and nailing through the trochanteric fossa.

OSTEOSYNTHESIS WITH INTRAMEDULLARY NAILS IN CHILDREN

The authors present a comprehensive review of the literature emphasizing the use of flexible intramedullary nails in the treatment of fractures in children, focusing the treatment of femoral shaft and forearm fractures and emphasizing the importance of the non-surgical approach. Children's age and weight threshold are not well defined for the use of the method. The removal of implants is a controversial matter in the literature, with a trend towards keeping the implants.

Soft tissue anatomy around the hip and its implications for choice of entry point in antegrade femoral nailing

Antegrade intramedullary nailing is an accepted method of treatment for femoral shaft fractures. Entrance of the nail through the trochanteric fossa is currently recommended by some surgeons. This approach results in some cases, however, in loss of abduction strength and persistent pain. Nail insertion at the tip of the greater trochanter may be more favorable. In this study the anatomical relationships of the trochanteric fossa and of the tip of the greater trochanter were explored. Dissection was carried out in 10 fresh human cadaver femurs. The risks and safety of the two entry points with respect to the adjacent soft tissues were assessed. Abductor muscles and tendons, branches of the medial circumflex femoral artery and the hip joint capsule were at risk during nail insertion through the trochanteric fossa. These structures were not endangered during insertion through the trochanteric tip. The reported clinical morbidity after nailing through the trochanteric fossa may result from direct soft tissue injury and may be reduced by choosing the route through the greater trochanter.

Muscle function and functional outcome following standard antegrade reamed intramedullary nailing of isolated femoral shaft fractures

OBJECTIVE

To evaluate the functional outcomes and long-term effects on muscle strength of femoral shaft fractures treated with intramedullary (IM) antegrade nailing using a standard piriformis start point.

DESIGN

Retrospective Outcome Study.

SETTING

Tertiary Level Teaching Hospital and Referral Centre for the Province of British Columbia.

PATIENTS/PARTICIPANTS

Twenty-one patients (7 female, 14 male; mean age 34.5 years, range 16-56 years) with isolated femoral shaft fractures who were treated with standard antegrade reamed interlocking IM nailing and who had a minimum 1-year follow-up were identified through the Orthopaedic Trauma Database. All patients had isokinetic muscle testing of their hip abductors, hip extensors, and knee extensors using the KinCom muscle testing machine. Of the patients, 10 underwent formal gait lab analysis. All of the patients answered a questionnaire and completed the Short Form (SF)-36 and Musculoskeletal Functional Assessment outcome measures.

INTERVENTION

Antegrade reamed interlocking IM nailing of femoral shaft fractures using a standard trochanteric fossa (also referred to as piriformis fossa) starting point.

MAIN OUTCOME MEASUREMENTS

Examination of muscle strength, using 2 different objective measures (KinCom and gait analysis). The KinCom muscle testing machine was used for isokinetic muscle testing of hip abductors, hip extensors, and knee extensors. Outcome questionnaires were used to evaluate function (Musculoskeletal Functional Assessment) and general health (SF-36).

RESULTS

Isokinetic muscle testing showed a statistically significant lower peak torque generation by the hip abductors (P=0.003) and hip extensors (P=0.046) from the uninjured contralateral side. The gait lab analysis did not show important changes in gait pattern. Scores for the SF-36 were 51.77+/-7.55 and 53.73+/-8.70. Scores for the Short Musculoskeletal Functional Assessment (S-MFA) were 7.74 and 8.66. Both scores did not indicate any significant disability.

CONCLUSIONS

Antegrade reamed interlocking IM nailing of femoral shaft fractures using a standard trochanteric fossa starting point is associated with a mild hip abductor muscle-strength deficit. Gait pattern returns to normal following femoral shaft fracture treated with this technique, and functional outcomes are good.

The locked flexible intramedullary humerus nail in pediatric femur and tibia shaft fractures: a feasibility study

There are several options for the treatment of long bone fractures in skeletally immature patients. Surgeon experience, type of fracture, and the possibility of damage to the physeal area dictate individual fracture management patterns. Notably, nail devices have not gained popularity in this patient group. Intramedullary locking nails have become the standard of care in adult patients due to decreased morbidity and mortality. A novel nail has been developed for humeral shaft fractures that uses a lateral starting position to avoid damage to the rotator cuff in humeral fracture fixation. This is possible because of the nail's transient flexibility during insertion. This study illustrates that it is feasible to insert this type of nail through multiple entry portals for both tibial and femoral fracture fixation, without damaging the physeal blood supply or growth areas.

Entry point soft tissue damage in antegrade femoral nailing: a cadaver study

INTRODUCTION

Little attention is paid to insertion site morbidity associated with antegrade femoral nailing. However, residual peritrochanteric pain after nailing is not uncommon. Additionally, the end branches of the medial femoral circumflex artery (m.f.c.a.) supplying the femoral head are in close proximity to the insertion site of the nail, and the occurrence of avascular necrosis of the femoral epiphysis after nailing in adolescents is rather frequent.

OBJECTIVE

The aim of this study was to assess iatrogenic soft tissue injuries at the site of nail insertion.

MATERIALS AND METHODS

Nailing with a reamed AO universal femoral nail was performed on sixteen adult cadavers followed by dissection of the proximal part of the femur to assess possible damage to the soft tissues. Three entry portals were defined. (A) entry portal lateral to the junction of the neck and the greater trochanter; (B) entry portal at the base of the greater trochanter anterior to a line along the longitudinal axis of the femoral neck; and (C) entry portal at the base of the greater trochanter posterior to a line along the axis of the femoral neck (at the piriformis fossa).

RESULTS

In Group A, partial avulsion of the piriformis and the obturator internus tendon were present in four and in one of five specimens, respectively. Group B showed injuries to the piriformis tendon in two and to the gluteus minimus tendon in one of four cases. In Group C, partial avulsion of the piriformis, obturator internus, and obturator externus tendon were encountered in five, six, and two of seven specimens, respectively. Anterior branches of the ramus profundus of the m.f.c.a. within the synovial fold were damaged in all of these cases.

CONCLUSION

To select the best nail entry portal, the ease of nail insertion must be weighed against the resulting soft tissue damage at the site of insertion. The nail entry portal at the piriformis fossa, although geometrically ideal and most recommended, causes the most significant damage to muscle and tendons as well as to the blood supply to the femoral head. Therefore, even if reported only once, the occurrence of avascular necrosis of the femoral head after nailing in adults is a possible complication of this nail entry portal. The authors therefore prefer to avoid this entry portal in every case. The nail entry portal anterior to the longitudinal axis of the femoral neck, as in group B, although better with respect to the soft tissue damage, has the worst geometric and biomechanical disadvantages. The results of the current study favor the nail entry portal lateral at the greater trochanter as in Group A, which is equal to the entry portal B with respect to the soft tissue damage but allows introduction of the nail into the medullar cavity without difficulties.