Knee in congenital short femur

Proximal Femoral Focal Deficiency/Congenital Femoral Deficiency: Evaluation and Management

Proximal focal femoral deficiency is a congenital transverse deficiency in which the femur is globally smaller with a typical proximal deformity at the hip that may include distal involvement of knees, leg, and feet. Congenital femoral deficiency (CFD) describes a broader spectrum of longitudinal deficiency inclusive of proximal focal femoral deficiency. CFD may also include lateral distal femoral hypoplasia, knee cruciate ligament deficiency, rotational instability, patellar dislocation, fibular hemimelia, ray absence, and contralateral limb involvement. Treatment intends to maximize function by limb equalization and deformity correction ranging from nonsurgical management using prosthetics to amputation and may include lengthening, shortening, and complex limb reconstruction. Management decisions depend on overall severity and the patient and family's preferences and priorities. Owing to its complexity, CFD is best treated by clinicians with considerable deformity treatment experience who can help guide decision making and embark on a treatment course that will maximize the functional outcome.

The knee in congenital femoral deficiency and its implication in limb lengthening: a systematic review

Congenital femoral deficiency (CFD) is a rare disorder with several limb anomalies including limb shortening and knee cruciate ligament dysplasia.

Limb lengthening is usually performed to correct lower limb discrepancy. However, complications, such as knee subluxation/dislocation, can occur during this treatment.

Here, we explore CFD knee abnormalities and knee dislocation during limb elongation, discussing when and whether knee ligament reconstruction prior to the lengthening would be necessary to reduce the risk of knee dislocation.

There is not enough support in the literature for the routine reconstruction of cruciate ligaments in CFD patients.

Of note, in cases of severe anteroposterior or posterolateral rotatory instability, cruciate ligament reconstruction might be considered to decrease the risk of knee subluxation/dislocation during the lengthening treatment.

Cite this article: EFORT Open Rev 2021;6:565-571. DOI: 10.1302/2058-5241.6.200075

Single time angular deformity correction and treatment of knee instability in congenital fibular hemimelia. A case report

BACKGROUND

Fibular hemimelia is the most frequently occurring congenital anomaly of long bones. These patients, among other deficiencies, have a poor development of the anterior cruciate ligament (ACL). Unless it causes clinically assessed instability of the knee, nonsurgical treatment is given. When surgical treatment is required, correction of angular limb deformity must be realized prior to ACL reconstruction.

METHODS

We present the case of a 16-year old patient with congenital fibular hemimelia. Physical examination showed genu valgum, anteromedial rotatory instability and recurvatum of the right knee. We decided to perform surgical correction of the angular deformities and ACL reconstruction in the same surgical time.

RESULTS

Twelve months after surgery, the patient had no evidence of clinical instability, with a range of motion from -5°-110° of the right knee. No claudication or gait instability was found. The KT-1000 arthrometer showed a difference of 2mm between both knees.

CONCLUSION

The ACL reconstruction and corrective osteotomies of angular deformities performed in a single surgical procedure had a good clinical result in a 12 month follow up-period, restoring stability of the knee and allowing a normal gait cycle.

Cruciate ligaments in proximal femoral focal deficiency: arthroscopic assessment

BACKGROUND

Because there is limited information concerning the cruciate ligaments in proximal femoral focal deficiency, knee arthroscopy was used to identify the changes of cruciate ligaments and their relation to the different types of this deficiency.

METHODS

Knee arthroscopy was performed in 21 consecutive patients with deficiency types III, IV, VII-IX using the Pappas classification. A new classification of the knee was created. It contains types I, II, III according to the findings of the anterior cruciate ligament (ACL) (type I: normal, type II: hypoplasia, type III: aplasia) and 3 subtypes A, B, C according to the findings of the posterior cruciate ligament (PCL) (type A: normal, type B: hypoplasia, type C: aplasia), respectively. Instrumented and radiologic drawer testing was provided additionally in 2010.

RESULTS

The changes of the cruciate ligaments were found in all but 1 patient. Type I was found in only 2 patients. In 1, both cruciate ligaments were intact (type IA). In the other patient, the ACL was intact, but the PCL was absent (type IC). Hypoplastic ACLs (type II) were found in 4 patients, namely in 3 patients with normal PCLs (type IIA), whereas in 1 patient the PCL was absent (type IIC). In the majority of patients, the ACLs completely failed (type III, 15 patients). Absence of both cruciate ligaments was found in 8 patients (type IIIC). PCLs were intact in 4 patients (IIIA) or were hypoplastic in 3 patients (IIIB), respectively. Instrumental drawer testing was not reliable in patients of our group. Radiologic testing showed a posterior shift of the tibia in the majority of patients on the affected side. Anterior and posterior drawer tests were increased in a majority of patients, but did not directly correlate to the presence/absence of cruciate ligaments.

CONCLUSIONS

Variable changes of the cruciate ligaments were found in all but 1 patient with proximal femoral focal deficiency. These changes were not related to the type of Pappas classification. Despite the lower clinical relevance of the changes in majority of patients, imaging of cruciate ligaments is recommend before lengthening of the extremity to avoid dislocation of the knee.

LEVEL OF EVIDENCE

I - Testing of previously developed diagnostic criteria in series of consecutive patients.

Lengthening of the congenital short femur using the Ilizarov technique: a single-surgeon series

We present a retrospective review of a single-surgeon series of 30 consecutive lengthenings in 27 patients with congenital short femur using the Ilizarov technique performed between 1994 and 2005. The mean increase in length was 5.8 cm/18.65% (3.3 to 10.4, 9.7% to 48.8%), with a mean time in the frame of 223 days (75 to 363). By changing from a distal to a proximal osteotomy for lengthening, the mean range of knee movement was significantly increased from 98.1 degrees to 124.2 degrees (p = 0.041) and there was a trend towards a reduced requirement for quadricepsplasty, although this was not statistically significant (p = 0.07). The overall incidence of regenerate deformation or fracture requiring open reduction and internal fixation was similar in the distal and proximal osteotomy groups (56.7% and 53.8%, respectively). However, in the proximal osteotomy group, pre-placement of a Rush nail reduced this rate from 100% without a nail to 0% with a nail (p < 0.001). When comparing a distal osteotomy with a proximal one over a Rush nail for lengthening, there was a significant decrease in fracture rate from 58.8% to 0% (p = 0.043). We recommend that in this group of patients lengthening of the femur with an Ilizarov construct be carried out through a proximal osteotomy over a Rush nail. Lengthening should also be limited to a maximum of 6 cm during one treatment, or 20% of the original length of the femur, in order to reduce the risk of complications.

[Femoral fracture in congenital femoral deficiency. A therapeutic challenge?]

There are no reports in the literature about femoral fractures in adults with congenital femoral deficiency. We report on a femoral fracture in a 60-year-old patient with congenital femoral deficiency. Despite early difficulties in mobilisation and delayed union after an angle-stable plate osteosynthesis, full weight bearing was reached after 8 months. The treatment of fractures in combination with congenital femoral deficiency remains difficult and depends on the extent of the defect, the complexity of the fracture, and associated anomalies. The objective of the often demanding operative treatment of a femoral fracture in combination with a congenital femoral deficiency should be reestablishment of the patient's walking ability.

Hip and knee dislocation during femoral lengthening in congenital short femur: a rare case report

Congenital short femur is a rare and complex deformity that is often associated with other anomalies. There are few reports of either hip or knee dislocations during femoral lengthening in congenital short femur predisposed by associated anomaly. However, there are probably no case reports of both hip and knee joint dislocation occurring in same case during femoral lengthening in congenital short femur. We have this case of congenital short femur, where both hip and knee dislocation occurs during femoral lengthening. We reviewed different article to understand the cause and avoid such unwanted complications in future.

[Lengthening of proximal femoral focal deficiency using a hybrid fixation with inclusion of the knee joint]

BACKGROUND

A major problem in lengthening a short femur in proximal focal deficiency of the femur (PFFD) is the development of contractures and dislocation of the hip and knee joint. The knee joint is particularly prone to dislocation because of the cruciate ligament insufficiency associated with PFFD. Axis deviations also need specific attention.

PATIENTS AND METHODS

In four patients (age 2.5-11 years) with PFFD (PAPPAS class III in one patient and VII in three patients), five femoral lengthenings with mechanical axis corrections were performed by the callotasis technique using a hybrid fixation system (Monotube/Triax) connecting the femur and the tibia with a fixed hinged knee joint to protect the knee against contracture and dislocation.

RESULTS

All patients retained their hip and knee function. Hip flexion contracture during lengthening may make inclusion of the hip joint into the fixation system necessary, but was not carried out in the four patients presented.

CONCLUSION

Four consecutive lengthenings of the femur with focal deficiency were carried out under protection by a hinged knee bridging external fixator. A dislocation could be prevented in all patients. We consider that such a system could be used during these lengthening procedures.

Knee arthritis in congenital short femur after Wagner lengthening

Knee anomalies are common in patients with congenital short femurs who require lengthening to correct limb-length discrepancies. We retrospectively reviewed the incidence of knee arthritis and the factors influencing its occurrence after femoral lengthening using the Wagner method. Twenty-three patients with congenital short femurs treated with the Wagner method were followed up until skeletal maturity (minimum, 5 years postoperatively). The mean age of the patients at lengthening was 10.8 years (range, 8.4-14.5 years). The mean leg-length discrepancy at the time of surgery was 9.7 cm (femur, 7.6 +/- 3.7 cm; tibia, 2.1 +/- 1.8 cm). Femoral lengthening (mean, 7.9 cm) was performed in 17 patients. Femoral lengthening and tibial lengthening were performed simultaneously in six patents (mean, 11.8 cm). The mean age of the patients at the last followup was 16.8 years (range, 14-20.3 years). Eighteen patients had arthritis at followup. Nine patients had severe arthritis develop, seven of whom had knee instability preoperatively and temporary subluxation during the lengthening procedure. Seventy-eight percent of patients had arthritis develop in the knee after lower-limb lengthening using the Wagner method for congenital short femurs. Patients who had an unstable knee before surgery had temporary knee subluxation develop during the lengthening procedure, and patients who had simultaneous lengthening of the femur and tibia had a high association with degenerative arthritis changes in the knee.

Knee reconstruction in syndromes with congenital absence of the anterior cruciate ligament

The authors review their experience with four patients with congenital deficiency of the anterior cruciate ligament (ACL) who underwent surgical treatment of symptomatic knee instability at a mean age of 15.8 years (range 14-17 years). Associated syndromes included fibular hemimelia, congenital short femur, and an unspecified skeletal dysplasia. All patients had undergone multiple previous realignment and leg lengthening procedures and were skeletally mature at the time of the reconstruction. All four patients underwent ACL reconstruction, and one patient underwent concomitant posterolateral corner reconstruction. One patient required an osteochondral autograft transplant procedure in addition to ACL reconstruction. Hypertrophy of the meniscofemoral ligament of Humphrey was a consistent anatomic finding at surgery. The patients were followed for a mean of 38 months (range 26-58 months) after the reconstruction. The mean preoperative Lysholm II score was 38 (range 28-56); the score had improved to a mean of 81 (range 78-93) at the latest follow-up. The authors conclude that reconstructive surgery is a viable option for restoration of knee stability and function in appropriately selected patients with congenital ACL deficiency.