Purpose
The aim of this study was to investigate the pathoanatomic features of patellar instability
by arthroscopically comparing patellofemoral congruence with rotation of the knee
joint and/or electrical stimulation of the quadriceps (ESQ) between knees with and
without patellar instability.
Methods
We retrospectively examined 83 knee joints in 83 patients. The joints were classified
into 2 groups: group 1 comprised those without a history of patellar dislocation and
included 59 patients (25 male and 34 female patients), and group 2 comprised those
with a history of patellar dislocation and included 24 patients (9 male and 15 female
patients). Evaluation of patellofemoral congruence at 30° of flexion of the knee joint
was conducted based on an axial radiograph and arthroscopic findings. The congruence
angle was measured on the radiograph. The position of the patellar central ridge (PPCR)
on the trochlear groove during arthroscopy was measured using still video frames of
knee joints with rotational stress and/or ESQ. Statistical differences in the measurements
between the 2 groups were assessed with the unpaired t test and the area under the receiver operating characteristic curve of each measurement.
Results
There were significant differences (P < .0001) between the 2 groups in the congruence angle on radiographs and PPCR in
knee joints with rotational stress and/or ESQ on arthroscopy. External and internal
rotation of the knee joint caused lateral and medial patellar shift, respectively,
in both groups, but the shift was significantly larger in group 2. ESQ in addition
to rotation caused further patellar shift in group 2 but reduced patellar shift in
group 1. Measurement of PPCR with external rotation of the knee and ESQ was the only
method to show an area under the receiver operating characteristic curve of 1.
Conclusions
There were significant differences in the effects of rotation of the knee joint and/or
ESQ on patellofemoral congruence at 30° of flexion of the knee joint on arthroscopy
between knees with and without patellar instability.
Level of Evidence
Level III, diagnostic study of nonconsecutive patients.
To read this article in full you will need to make a payment
Purchase one-time access:
Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online accessOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to ArthroscopyAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- Roentgenographic analysis of patellofemoral congruence.J Bone Joint Surg Am. 1974; 56: 1391-1396
- The abnormal lateral patellofemoral angle: A diagnostic roentgenographic sign of recurrent patellar subluxation.J Bone Joint Surg Am. 1978; 60: 55-60
- The tangential x-ray investigation of the patellofemoral joint: X-ray technique, diagnostic criteria and their interpretation.Clin Orthop Relat Res. 1979; : 16-26
- Axial and lateral radiographs in evaluating patellofemoral malalignment.Am J Sports Med. 1999; 27: 580-584
- Patellofemoral joint: 30 degrees axial radiograph with lateral rotation of the leg.Radiology. 1989; 170: 566-567
- A modified system of stress radiography for patellofemoral instability.J Bone Joint Surg Br. 2003; 85: 1128-1133
- Patellofemoral joint motion: Evaluation by ultrafast computed tomography.Skeletal Radiol. 1988; 17: 487-492
- Patellar tracking abnormalities: Clinical experience with kinematic MR imaging in 130 patients.Radiology. 1989; 172: 799-804
- In vivo tracking of the human patella using cine phase contrast magnetic resonance imaging.J Biomech Eng. 1999; 121: 650-656
- The arthroscope in the diagnosis of disorders of the patellofemoral joint.Clin Orthop Relat Res. 1979; : 45-50
- An arthroscopic method for lateral release of subluxating or dislocating patella.Clin Orthop Relat Res. 1982; : 9-18
- Arthroscopic evaluation and treatment of patellar malalignment.Clin Orthop Relat Res. 1984; : 122-128
- Arthroscopic determination of patellofemoral malalignment.Clin Orthop Relat Res. 1987; : 243-247
- Physical and arthroscopic examination techniques of the patellofemoral joint.J Orthop Sports Phys Ther. 1998; 28: 277-285
- Patellofemoral realignment: Dynamic intraoperative assessment.Iowa Orthop J. 2005; 25: 160-163
- Intra-operative femoral nerve stimulation as an aid in tibial tuberosity transfer.Ann R Coll Surg Engl. 2005; 87: 288-289
- Modifications of the Fulkerson osteotomy: A pilot study assessment of a novel technique of dynamic intraoperative determination of the adequacy of tubercle transfer.Iowa Orthop J. 2007; 27: 61-64
- Association of internal rotation of the knee joint with recurrent subluxation of the lateral meniscus.Arthroscopy. 2011; 27: 1071-1078
- Proximal superomedial portal in arthroscopy of the knee.Arthroscopy. 1991; 7: 246-251
- Axial linear patellar displacement: A new measurement of patellofemoral congruence.Am J Sports Med. 2009; 37: 970-973
- The three-dimensional tracking pattern of the human patella.J Orthop Res. 1990; 8: 372-382
- Effects of tibial rotations on patellar tracking and patella-femoral contact areas.J Biomed Eng. 1992; 14: 329-343
- Patellar tracking measurement in the normal knee.J Orthop Res. 1995; 13: 115-122
- Measurement of varus-valgus and internal-external rotational knee laxities in vivo—Part II: Relationship with anterior-posterior and general joint laxity in males and females.J Orthop Res. 2007; 25: 989-996
- Gender differences in trochlear groove orientation and rotational kinematics of human knees.J Orthop Res. 2009; 27: 871-878
- Patellofemoral pain.Instr Course Lect. 1992; 41: 57-71
- Arthroscopic examination of the patellofemoral joint using a central, one-portal technique.Orthop Clin North Am. 1986; 17: 263-268
- Intra-articular pressures during arthroscopic knee surgery.Arthroscopy. 1986; 2: 264-269
- Effects of joint angle, electrodes and waveform on electrical stimulation of the quadriceps and hamstrings.Ann Biomed Eng. 1988; 16: 299-310
- Quadriceps femoris muscle torques and fatigue generated by neuromuscular electrical stimulation with three different waveforms.Phys Ther. 2001; 81: 1307-1316
- Recruitment patterns in human skeletal muscle during electrical stimulation.Phys Ther. 2005; 85: 358-364
- Spatial fiber type distribution in normal human muscle. Histochemical and tensiomyographical evaluation.J Biomech. 2005; 38: 2451-2459
Article Info
Publication History
Published online: January 02, 2014
Accepted:
November 7,
2013
Received:
April 7,
2013
Footnotes
The authors report that they have no conflicts of interest in the authorship and publication of this article.
Identification
Copyright
© 2014 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.
