REHABILITATION FOLLOWING MEDIAL PATELLOFEMORAL LIGAMENT RECONSTRUCTION FOR PATELLAR INSTABILITY

Abstract

Patellar instability is a common problem seen by physical therapists, athletic trainers and orthopedic surgeons. Although following an acute dislocation, conservative rehabilitation is usually the first line of defense; refractory cases exist that may require surgical intervention. Substantial progress has been made in the understanding of the medial patellofemoral ligament (MPFL) and its role as the primary stabilizer to lateral patellar displacement. Medial patellofemoral ligament disruption is now considered to be the essential lesion following acute patellar dislocation due to significantly high numbers of ruptures following this injury. Evidence is now mounting that demonstrates the benefits of early reconstruction with a variety of techniques. Recently rehabilitation has become more robust and progressive due to our better understanding of soft tissue reconstruction and repair techniques. The purpose of this manuscript is to describe the etiology of patellar instability, the anatomy and biomechanics and examination of patellofemoral instability, and to describe surgical intervention and rehabilitation following MPFL rupture.

Level of evidence: 5.

Keywords: Knee; patellar instability; rehabilitation; surgery.

Figure 1.

A image of the medial aspect of the right knee with the patella at the top. The MPFL, passing over the forceps, links the proximal half of the medial border of the patella to the medial femoral condyle. The superficial fascia and distal part of the vastus medialis obliquus have been removed. Permission granted by Mountney J, Senavongse W, Amis AA, Thomas NP.Tensile strength of the medial patellofemoral ligament before and after repair or reconstuction. J Bone Joint Surg. 2005;87B(1):36-40.

Figure 2.

Examination of passive patellar mobility. A) The examiner uses thumb to determine midline of patella to determine amount of translation, B) translation of the patella in the lateral direction assessing the amount of passive patellar mobility. Following MPFL reconstruction the desired amount of passive patellar mobility should be approximately 2 quadrants or half the width of the patella.

Figure 3.

Pre-operative lateral patellar displacement with knee positioned in flexion. Taken from: Manske RC, Lehecka BJ, Prohaska D. Medial patellofemoral ligament reconstruction for patellar instability. SPTS Home Study Course, Indianapolis, IN. 2010.

Figure 4.

Pre-operative lateral patellar displacement with knee positioned in full extension. Taken from: Manske RC, Lehecka BJ, Prohaska D. Medial patellofemoral ligament reconstruction for patellar instability. SPTS Home Study Course, Indianapolis, IN. 2010.

Figure 5.

Diagnostic arthroscopy demonstrating patellar instability.

Figure 6.

Location of double incisions used for MPFL reconstruction. Taken from: Manske RC, Lehecka BJ, Prohaska D. Medial patellofemoral ligament reconstruction for patellar instability. SPTS Home Study Course, Indianapolis, IN. 2010.

Figure 7.

solating hamstring tendons used for MPFL reconstruction. Taken from: Manske RC, Lehecka BJ, Prohaska D. Medial patellofemoral ligament reconstruction for patellar instability. SPTS Home Study Course, Indianapolis, IN. 2010.

Figure 8.

After graft fixation, tension is set so that there is no undue tension on the medial side. The graft should become a passive tether, not to create a medial pull. Taken from: Manske RC, Lehecka BJ, Prohaska D. Medial patellofemoral ligament reconstruction for patellar instability. SPTS Home Study Course, Indianapolis, IN. 2010.

Figure 9.

Post-operative lateral patellar translation at 30 degrees of flexion showing excellent stability. Taken from: Manske RC, Lehecka BJ, Prohaska D. Medial patellofemoral ligament reconstruction for patellar instability. SPTS Home Study Course, Indianapolis, IN. 2010.

Figure 10.

Treatment of a hypomobile patellofemoral joint following MPFL reconstruction. Lack of passive mobility following reconstruction is one of the most common causes of surgical failure. If the athlete does not have a minimum of 2 quadrants passive patellar mobility, medial and lateral glide patellofemoral joint mobilizations may be required.

Figure 11.

Obtain early full knee extension to prevent flexion contracture.

Figure 12.

Performance of squat exercise on a balance board providing not only lower extremity strengthening but also a proprioceptive and balance training effect.

Figure 13.

Squatting on a leg press can increase the tolerable load in a controlled fashion.

Figure 14.

Lateral band walking provides a method of incorporating additional strengthening effect to the hip abductors which are important proximal stabilizers to the leg and improves knee control.

Figure 15.

Hip abductors are recruited highly with the lateral band walking drill.

Figure 16.

A. Hip hike in the down position, B. Hip hike in the up position.

Figure 17.

A. Single-leg squat can be performed to examine more functional movement patterns of the entire lower extremity. A) The patient demonstrates poor frontal, transverse and sagittal control. B) improved control is assisted by visualization in front of mirror and verbal cues.

Figure 18.

Bilateral jumping without pain or symptoms.