Effect on knee motion of gradual intramedullary femoral lengthening

Gradual femoral lengthening causes loss of knee motion due to soft tissue tightness. Lengthening with an intramedullary device would be expected to retain good knee movements since it avoids soft tissue transfixation. To ascertain this we looked at the knee movements recorded in 27 patients before, during and after bilateral simultaneous femoral lengthening using Albizzia nails. The mean gain was 6.2 cm and the mean follow-up 28.6 months. No significant difference was noted between the mean preoperative and final knee flexions (148.3 degrees vs. 148.4 degrees) and the mean preoperative and final knee extensions (2.3 degrees vs. 3.4 degrees). By their last visit, all patients were flexing to at least 120 degrees and only one patient had a flexion deformity over 5 degrees. Thus maintenance of good knee motion and early return to activities is possible when an intramedullary device like the Albizzia nail is used for femoral lengthening.     

Problems, obstacles and complications of femoral lengthening with the use of the Italian modification of the Ilizarov device]

The results of femoral lengthening using the Italian modification of the Ilizarov are presented. Mean age of the patients was 14 years (ranging from 7 to 29). The most frequent etiology of limb shortening was femoral hypoplasia (7 patients) and sequelae of septic arthritis of the hip and/or the knee (6 patients). Indications for surgical treatment were limb shortening from 3 to 12 cm (mean 6.5 cm), along with axial deviation ranging from 10 degrees to 40 degrees in 6 patients. Mean follow-up time was 15 months (ranging from 6 to 35 months). The Ilizarov apparatus was based on two distal rings, stabilized by "K" wires, and proximally by a ring connected with an Italian femoral arch, stabilized by a Schanz screw. Planned lengthening (ranging from 3.5 cm to 12 cm) was achieved in all treated patients. The healing index ranged from 0.8 to 2.1 month/cm (mean 1.4). Problems, obstacles and complications were analyzed according to the Paley classification. In all 16 patients without primary knee stabilization, limited knee flexion ranging from 5 degrees to 90 degrees (mean 40 degrees) was noted during the distraction phase, which didn't improve significantly during the consolidation phase. Knee flexion improved to a mean 90 degrees after a 6 month follow-up. Bone regenerate defects (cysts, narrowing) were noted in 4 patients. Secondary knee stabilization was performed in 2 cases. In the first case because of knee pain and a severe limitation of knee motion. In the second, during a revision procedure because of distal femur angulation. Premature consolidation was noted in one patient and was treated by osteotomy. In one case axial deviation during the consolidation phase required osteotomy. In another case a fracture of the femur was treated by a plaster cast. In one case 1.5 years after the lengthening procedure subluxation of the hip was noted. Permanent knee flexion limitation to less than 90 degrees was noted in 6 patients. Femoral lengthening with the use of the Italian modification of the Ilizarov device give a high incidence of knee range of motion limitation, which can be decreased by preserving more than 30 degrees knee flexion during the distraction phase.     

改良双侧胫肌延长术的疗效分析

目的 探讨改良双侧胫骨延长术的治疗效果。方法 1997年5月－2000年5月对32例患者行双侧胫骨延长达到增高目的,其中8例膝内翻。手术为颈骨结节下1．0cm处骨膜下横形截断胫骨,腓骨于外踝上10cm水平处横形截断,胫肌骨置入带锁髓内钉,近端上锁,小腿外置延长器,每日缓慢牵伸延长胫骨,达到预期延长目的后2周拆除延长器,同时带锁髓内钉远端上锁,延长段骨质完全愈合约1年后取出带锁髓内钉。结果 32例术后双侧胫骨延长3．5－12．0cm,平均8．5cm,延长时间为53－180天,平均128天,延长段骨痂生长时间为120－270天,平均180天,随访1－3年,患者在增高高度、步态及关节活动度等方面满意率达98％。结论 改良后的双侧胫肌延长术,胫骨骨折愈合时间缩短,并发症少,可同时矫正膝内、外翻畸形。     

Retrograde Marknagelung bei periprothetischen Frakturen des distalen Femurs

Objective

Intramedullary stabilization of periprosthetic distal femoral fractures by interlocking nailing. Closed reduction by retrograde nail can be combined with the use of transmedullary support screws (TMS principle of Stedtfeld).

Indications

Supracondylar fractures above stable knee arthroplasty (Rorabeck types I and II), femoral shaft fractures ipsilateral of stable hip and/or knee arthroplasty, contraindications for antegrade nailing

Contraindications

Closed box design of femoral implant, intercondylar distance of the femoral component smaller than nail diameter, more than 40° flexion deficit of the knee, inability to place two bicortical distal interlocking screws. Relative contraindication: insufficient overlap with proximal implants

Surgical technique

Supine position and knee flexion of approximately 45°. Fluoroscopy should be possible between the knee and hip. Longitudinal skin incision into the pre-existing scar over the patellar tendon which is then split. The nail entry point is located in the intercondylar groove at the deepest point of Blumensaat’s line, often predetermined by the femoral arthroplasty component. Reaming is rarely necessary. Transmedullary support screws may correct axial malalignment during nail insertion. Static interlocking in a direction from lateral to medial by the aiming device. Insertion of locking cap.

Postoperative management

Retrograde nailing normally allows full weight bearing. Range of motion does not need to be restricted.

Results

Out of 101 fractures treated between 2000 and 2013 with a Targon RF nail (Aesculap, Tuttlingen, Germany) 10 were periprosthetic, all were classified as Rorabeck type II and of these 6 fractures were metaphyseal and 4 were diaphyseal. In four cases proximal implants were present. The mean operative time for periprosthetic fracture fixation did not significantly differ from that for normal retrograde femoral nailing. There were no postoperative infections, fixation failures or delayed unions. There was one revision for secondary correction of maltorsion.     

In vivo three-dimensional knee kinematics using a biplanar image-matching technique.

A biplanar image-matching technique was developed and applied to a study of normal knee kinematics in vivo under weightbearing conditions. Three-dimensional knee models of six volunteers were constructed using computed tomography. Projection images of the models were fitted onto anteroposterior and lateral radiographs of the knees at hyperextension and every 15 degrees from 0 degrees to 120 degrees flexion. Knee motion was reconstructed on the computer. The femur showed a medial pivoting motion relative to the tibia during knee flexion, and the average range of external rotation associated with flexion was 29.1 degrees . The center of the medial femoral condyle translated 3.8 mm anteriorly, whereas the center of the lateral femoral condyle translated 17.8 mm posteriorly. This rotational motion, with a medially offset center, could be interpreted as a screw home motion of the knee around the tibial knee axis and a posterior femoral rollback in the sagittal plane. However, the motion of the contact point differed from that of the center of the femoral condyle when the knee flexion angle was less than 30 degrees. Within this range, medial and lateral contact points translated posteriorly, and a posterior femoral rollback occurred. This biplanar image-matching technique is useful for investigating knee kinematics in vivo.     

The treatment of noninfected pseudarthrosis of the femur and tibia with locked intramedullary nailing

Sixty-six cases of noninfected nonunions (27 femoral and 39 tibial) were treated with an interlocking nail. In these cases, 92.6% of the femurs and 94.8% of the tibias healed after the first operation in a mean time of 15.4 and 13.0 weeks, respectively. Deep infection complicated five nailings (7.5%, two femur and three tibia), which included three patients with reactivation of latent osteomyelitis. All cases healed after debridement and use of gentamicin PMMA beads. In one case the nail had to be removed and replaced by an external fixator. Residual angulation between 5 degrees and 10 degrees occurred in three femurs and seven tibias. Shortening occurred in all patients and averaged 0.9 cm in the femur and 0.5 cm in the tibia. Of the patients treated for femoral nonunion, 92.5% achieved full hip flexion and 77.8% full knee flexion on final follow-up examination. In patients with tibial nonunions treated with a locked nail, 92.3% had normal knee flexion and 84.6% obtained normal ankle function. Interlocking nailing offers unique advantages to patients with femoral or tibial shaft pseudarthrosis. The technique allows early weight-bearing, range of motion of adjacent joints, and reliable rates of consolidation of the nonunions.     

Quadricepsplasty for knee stiffness after femoral lengthening in congenital short femur

We review the results of a modified quadricepsplasty in five children who developed stiffness of the knee after femoral lengthening for congenital short femur using an Ilizarov external fixator which spanned the knee. All had a full range of movement of the knee before lengthening was undertaken. Unifocal lengthening was carried out in the distal metaphysiodiaphyseal region of the distal femur with a mean gain of 6.5 cm. The mean percentage lengthening was 24%. At the end of one year after removal of the Ilizarov frame and despite intensive physiotherapy all patients had stiffness. Physiotherapy was continued after the quadricepsplasty and, at the latest follow-up (mean 27 months), the mean active flexion was 102 degrees (80 to 130). The gain in movement ranged from 50 degrees to 100 degrees. One patient had a superficial wound infection which settled after a course of oral antibiotics. None developed an increased extension lag after surgery and all were very satisfied with the results. Quadricepsplasty is a useful procedure for stiffness of the knee after femoral lengthening which has not responded to physiotherapy.     

Use of the Dynastab-K (knee) external fixator technique for functional treatment of intra- and peri-articular fractures of the knee joint]

The aim of this study was to validate the results of treatment of articular fractures using a Dynastab-K (knee) external fixator, which gives a good stabilisation, while retaining motion in the knee joint. A group of 6 patients with articular fractures of the knee joint was evaluated. Two fractures were located within the distal femur and 4 within the tibial plateau. After anatomical reposition of the bone fragments primary stabilisation was achieved by means of the Dynastab-K fixator and maintained for a period of 8-10 weeks. Passive motion of the knee was implemented in the first post-op day and active motion was implemented in the third post-op day. In all cases proper healing of the fractures, full extension and a minimally limited flexion (100 degrees) were achieved. Flexion limitation was corrected by means of an intensive rehabilitation programme. Use of the presented technique allows proper stabilisation of the bone fragments with maintenance of joint motion throughout treatment. Basing on our observations we concluded that implementation of an articulated external fixator in articular fractures of the knee leads to proper fracture healing with minimal loss of motion, which can be resolved by rehabilitation procedures.     

The results of quadricepsplasty on knee motion following femoral fractures

Knee motion following femoral fractures is often less than satisfactory. Surgical procedures to increase knee motion are rarely done. This paper presents a series of nine patients who had severe femoral fractures, primarily in the distal third. Once union was obtained, all patients had knee flexion incompatible with normal gait (average 30.2 degrees). All patients underwent a quadricepsplasty at Rancho Los Amigos Medical Center. Eight of the nine achieved knee flexion allowing normal gait (average 78 degrees). This paper presents our indications, methods, results, and complications in performing quadricepsplasty to achieve knee flexion following femoral fractures.     

Rectus femoris transfer for children with cerebral palsy: long-term outcome

The purpose of this study was to evaluate the long-term results of rectus femoris transfer in cerebral palsy children with stiff-knee gait. Thirty-eight affected limbs in 24 children were evaluated preoperatively and 1 year postoperatively by gait analysis, with 26 limbs in 18 patients having final study, averaging 4.6 years postoperatively. Functional ambulatory status was evaluated based on Hoffer's criteria on ambulation. There were statistically significant improvements of 9.8 degrees in maximum swing-phase knee flexion and 7.0 degrees in total range of knee motion at 1 year, with a small loss of knee extension in stance. At final gait analysis, the improvement in the swing-phase knee flexion was maintained, but improvement in total range of knee motion was decreased. There were no significant changes in temporal parameters. Improvement in swing-phase knee flexion and foot clearance after rectus femoris transfer was associated with loss of knee extension at long-term follow-up. Hamstring lengthening in patients who develop excessive stance-phase knee flexion may be necessary.     

Retrograde femoral nailing: a focus on the knee

A consecutive series of 23 patients with reamed retrograde femoral nails was reviewed. Nails were placed through the intercondylar notch with a minimal incision. Nineteen patients with retrograde femoral nails were available at an average follow-up of 19.3 months. The union rate was 100% with no infections or malunions. No second surgeries were required for union. Knee range of motion averaged 109 degrees and was greater in those patients with shaft fractures (117 degrees) than in those with supracondylar-intercondylar fractures (91.3 degrees) (P=.02). Pain (0-3 scale) averaged 0.36. Hospital for Special Surgery knee scores averaged 80.4 (90% good or excellent results). Minor knee pain (55%) and secondary surgeries (35%) were common. The only fair or poor results were in patients with preexisting osteoarthritis. A literature review of 14 papers and abstracts was conducted. Exposure, often extensive initially, is more recently percutaneous. The infection rate is acceptable (0-14%), with knee sepsis uncommon. Lower union rates were observed for supracondylar femur fractures (80%-84%) than for femoral shaft fractures (85%-100%) after a single surgery. Second surgeries are common (14%-60%). Varus/valgus malunion, common (12%-29%) with the initial extrarticular entry site, occurs less with the intercondylar entry site. The antegrade femoral nail allows for better control of proximal shaft fractures, while the retrograde femoral nail is more reliable in controlling distal shaft fractures. Rotational malunion still remains a problem. Mild knee pain is common (13%-60%). The treatment of supracondylar femur nonunions with retrograde femoral nailing is disappointing.     

Results of femoral lengthening over an intramedullary nail and external fixator

INTRODUCTION: Current techniques of operative limb lengthening usually are based on distraction osteogenesis. One of the techniques is limb lengthening over an intramedullary nail. AIM OF PAPER: The goal of this study is to evaluate the results of femoral lengthening over an intramedullary nail. MATERIAL: Between 1999 and 200619 femoral "over nail" lengthenings were performed. There were 7 males and 12 females. Mean patients' age at surgery was 15.8 years, and mean initial femoral shortening was 5.1 cm. Operative technique consisted of one-stage implantation of intramedullary nail and external fixator. Ilizarov apparatus was used in 9 patients, monolateral fixator in 10 cases--ORTHOFIX in 9 patients, Wagner fixator--in 1 patient. Intramedullary nail was locked proximally with screws or Schanz pins from external fixator. After distraction phase, external fixator was removed and distal locking screws were applied. METHODS: Evaluation criteria: obtained lengthening, time of external fixator, treatment time, healing index, external fixation index, range of motion in hip and knee joints and complications according to Paley. RESULTS: The mean lengthening was 4.6 cm, and mean distraction time was 66.6 days. Mean time of external fixation was 115.5 days, and external fixation index was 26.2 days for centimeter. Healing index was 36.9 days for centimeter. In cases with monolateral fixator, healing index did not differ with the whole group. During treatment 18 complications occurred, for a rate of 0.9 complication per segment. CONCLUSIONS: Lengthening over an intramedullary nail reduces the time of external fixator. Over nail femoral lengthening can prevent axis deviation following regenerate bending. Complication rate is similar to lengthenings with the classic Ilizarov technique. There are no differences in the treatment time in relation to the type of external fixator.     

股骨髁上交锁髓内钉治疗股骨远端粉碎骨折

目的：评价股骨髁上交锁髓内钉治疗股骨远端粉碎骨折的效果。方法：应用股骨髁上交锁髓内钉治疗股骨远端骨折37例,闭合及小切口开放复位,做膝关节小切口,从股骨髁间窝处插入交锁髓内钉治疗股骨髁上皮髁间粉碎骨折,结果：37例切口顺利愈合,无关节感染发生,骨折复位好,35例骨愈合平均12．4周,膝关节屈曲平均105度,结论：股骨髁上交锁髓内钉手术操作简单,固定可靠,对软组织破坏少,骨愈合率明显,骼于治疗股骨远端复杂骨折手术效果好。     

Knee mobility in femoral lengthening using Ilizarov's method

Muscle contracture and joint stiffness are a major concern during limb lengthening using the Ilizarov method. The aim of this study was to detect factors that may influence the final loss of knee flexion. We retrospectively studied knee movement in 32 patients undergoing femoral lengthening using the Ilizarov method. The pattern of loss of knee movement showed a rapid fall in knee flexion during the latency period between operation and start of distraction, and the flexion loss continued during lengthening. There was a relationship between the worst knee range of motion achieved during lengthening and the final loss of knee flexion. Intensive physical therapy is necessary in the latency period, because there is a rapid decrease in knee flexion, as well as during the whole lengthening procedure, in which flexion loss continues. Despite the flexion loss, patients finally regain good knee function after removal of the external fixator.     

Femoral lengthening over a humeral intramedullary nail in preadolescent children

BACKGROUND: Femoral lengthening over an intramedullary nail has been described in adults. A technique of femoral lengthening over a humeral intramedullary nail in children is described, and the results and complications are presented. METHODS: Nine preadolescent patients (average age, nine years and ten months) with femoral length discrepancy were treated with femoral lengthening over a humeral intramedullary nail. After nail insertion, a monolateral external fixator was placed with half-pins either anterior or posterior to the intramedullary nail, and lengthening was performed through a proximal osteotomy. RESULTS: The femora were lengthened a mean of 6.1 cm (range, 5.0 to 8.0 cm), 19.5% (range, 15.9% to 26.2%) of the preoperative femoral length. Patients had a mean lengthening index of 12.2 days/cm of length (range, 9.5 to 16.9 days/cm of length). Five complications including osteomyelitis, failure of the distal interlocking site, and femoral fracture at the distal end of the nail occurred in four patients; four of the complications led to surgical intervention. No case of proximal femoral valgus secondary to nailing through the greater trochanter had developed by the time of final follow-up. All patients were followed for a minimum of two years postoperatively, with a mean of 128 weeks (range, 111 to 161 weeks). CONCLUSIONS: The technique is effective but has a high rate of complications, including osteomyelitis, which developed in two of the nine patients. No avascular necrosis or proximal femoral valgus was noted.     

A Comparison of Femoral Lengthening Methods Favors the Magnetic Internal Lengthening Nail When Compared with Lengthening Over a Nail

Background

Bone lengthening with an internal lengthening nail (ILN) avoids the need for external fixation and requires one less surgical procedure than lengthening over a nail (LON). However, LON has been shown to be superior to femoral internal lengthening using a mechanical nail. The magnetic ILN, a remote-controlled and magnet-driven device, may have overcome the weaknesses of earlier internal lengthening technology and may be superior to LON.

Questions/Purposes

(1) Is the magnetic ILN more accurate than LON for femoral lengthening? (2) Does the magnetic ILN demonstrate more precise distraction rate control than LON? (3) Does the magnetic ILN result in faster regenerate site healing, with more robust callus, than LON? (4) Does the magnetic ILN result in fewer complications, including impediments to knee motion, than LON?

Methods

We conducted a retrospective comparison of the records and radiographs of 21 consecutive patients with 22 femoral lengthenings using LONs and 35 consecutive patients with 40 femoral lengthenings using remote-controlled magnetic ILNs. Primary outcomes measured included accuracy, distraction rate precision, time to bony union, final knee range of motion, regenerate quality, and complications. The minimum follow-up times for the LON and ILN cohorts were 13 and 21 months, respectively.

Results

Patients treated with ILN had a lower post-treatment residual limb-length discrepancy (0.3 mm) than those treated with LON (3.6 mm). The rate of distraction was closer to the goal of 1 mm/day and more tightly controlled for the ILN cohort (1 mm/day) than that for the LON group (0.8 mm/day; SD, 0.2). Regenerate quality was not significantly different between the cohorts. Bone healing index for ILN was not statistically significant. Time to union was shorter in the ILN group (3.3 months) than that in the LON group (4.5 months). A lower percentage of patients experienced a complication in the ILN group (18%) than in the LON group (45%). Knee flexion at the end of distraction was greater for ILN patients (105°) than that for LON patients (88.8°), but this difference was no longer observed after 1 year.

Conclusions

Femoral lengthening with magnetic ILN was more accurate than with LON. The magnetic ILN comports the additional advantage of greater precision with distraction rate control and fewer complications. Both techniques afford reliable healing and do not significantly affect knee motion at the final follow-up. The magnetic ILN method showed no superiority in regenerate quality and healing rate.

     

Muscle strength and knee range of motion after femoral lengthening

Background and purpose — Femoral lengthening may result in decrease in knee range of motion (ROM) and quadriceps and hamstring muscle weakness. We evaluated preoperative and postoperative knee ROM, hamstring muscle strength, and quadriceps muscle strength in a diverse group of patients undergoing femoral lengthening. We hypothesized that lengthening would not result in a significant change in knee ROM or muscle strength.

Patients and methods — This prospective study of 48 patients (mean age 27 (9–60) years) compared ROM and muscle strength before and after femoral lengthening. Patient age, amount of lengthening, percent lengthening, level of osteotomy, fixation time, and method of lengthening were also evaluated regarding knee ROM and strength. The average length of follow-up was 2.9 (2.0–4.7) years.

Results — Mean amount of lengthening was 5.2 (2.4–11.0) cm. The difference between preoperative and final knee flexion ROM was 2° for the overall group. Congenital shortening cases lost an average of 5% or 6° of terminal knee flexion, developmental cases lost an average of 3% or 4°, and posttraumatic cases regained all motion. The difference in quadriceps strength at 45° preoperatively and after lengthening was not statistically or clinically significant (2.7?Nm; p = 0.06). Age, amount of lengthening, percent lengthening, osteotomy level, fixation time, and lengthening method had no statistically significant influence on knee ROM or quadriceps strength at final follow-up.

Interpretation — Most variables had no effect on ROM or strength, and higher age did not appear to be a limiting factor for femoral lengthening. Patients with congenital causes were most affected in terms of knee flexion.     

One- and two-strand posterior cruciate ligament reconstructions: cyclic fatigue testing.

This study examined how one- and two-strand posterior cruciate ligament (PCL) reconstructions resist the return of posterior translation during repetitive knee cycling. The femoral attachment of the one-strand graft and the anterior strand of the two-strand (AD2) grafts were located within the anterior one-third of the femoral PCL footprint. The second strand was placed within the middle third of the femoral footprint in one of three locations: middle-distal (MD), middle-middle (MM), or middle-proximal (MP). During repetitive knee cycling from 5 degrees to 120 degrees flexion with a 100 N posterior force, the intact knee had less than 1mm of residual posterior translation after 2048 flexion-extension cycles. Under similar cyclic conditions, the AD2-MM reconstruction achieved the most cycles before failure; however, this two-strand configuration failed in less than 700 cycles. The other reconstructions, either one strand or two strand, failed in less than 350 cycles. The surface failure location for 19 of 25 graft strands was within the femoral one-third of the strand. We concluded that one- and two-strand reconstructions under moderate loading and a range of motion from 5 degrees to 120 degrees flexion have an unacceptably high cyclic failure rate suggesting modifications of the allowable postoperative knee flexion and loading.